trinomial 
(term), + -ill. Cf. binomial.} I. a. 1. In zniil. 
and bot. : (a) Consisting of three terms, as the 
technical name of a subspecies; trionymal: 
thus, the name Certliia fauiiliiiriti /iincricinin is 
trinomial. See binomial, polynomial, (b) Using 
or admitting trinomial or trionymal names in 
certain cases: as, the trinomial system of no- 
menclature. Also trinnminul. 2. In ?</., con- 
sisting of three terms connected by either of 
the signs + and : thus, it + b + c, or J 2 2.r# 
-f / 2 is a trinomial quantity. 
II. . 1. A technical name consisting of three 
words, of which the first is the name of the 
genus, the second that of the species, and the 
third that of a geographical race, subspecies, 
or variety ; a trionym. The use of trinomials, for- 
merly interdicted and supposed to be contrary to the 
canons of nomenclature, has of late become common, es- 
pecially among American naturalists. (See trfaomtemm.) 
A name of three terms the second of which is a generic 
name in parenthesis (see ytibgcnux) does not constitute a 
trinomial, and no proper trinomial admits any mark of 
punctuation, or any word or abbreviation, between its 
three terms. Thus : Qttercus coccinea var. tinctoria is not 
a pure trinomial. 
2. In alg., a trinomial expression. See I., 2. 
triiiomialism (tri-no'mi-al-izm), n. [< trinomi- 
al + -ism.'] The practice of naming objects of 
natural history in three terms ; the use of tri- 
nomials, or that system of nomenclature which 
admits them; trionymal nomenclature. Trino- 
mialism is one of the two most distinctive features of 
what is called the American school in zoology, the begin- 
ning of the zoological system with 1758 (instead at 1766: 
see synonym, 2) being the other; and it has been advo- 
cated with special persistency by the ornithologists. 
trinomialist (tri-uo'mi-al-ist), . [< trinomial 
+ -ist.} One who uses trinomials or favors the 
trinomial system of nomenclature. 
trinomialityftri-no-mi-al'i-ti), n. [< trinomial 
+ -ity.} The character of being trinomial; the 
expression of a name in three words ; trinomi- 
alism. See trinomial, n., 1. 
trinomially (tri-no'mi-al-i), adv. According to 
the principles or by the method of trinomialism ; 
by the use of trinomials: in any given case, as 
that cited in the quotation, implying the re- 
duction of what had been before rated as a 
full species to the rank of a conspecies or sub- 
species. 
There has been quite a consensus of opinion among some 
of the German ornithologists that they [the yellow wag- 
tails] ought to be treated trinomially. Nature, XXX. 257. 
trinominal (tri-nom'i-nal), .. [< L. trinominis, 
having three names, < tres (tri-), three, + no- 
men, name : see nominal. Cf . trinomial.'} Same 
as trinomial, a., 1. Also trionymal. 
trinquett. An obsolete spelling of trinket 1 , 
trinket 3 . 
trintle (trint'l), . A dialectal (Scotch) variant 
of trindle. 
trinuniont (trin-u'nyon), n. [< L. trirnts, three- 
fold, + nnio(n-), union : see trine 3 and union.] 
A trinity. [Rare.] 
But that same onely wise Trin-mion 
Workes miracles, wherein all wonder lies. 
Davies, Microcosmos, p. 79. {Dames.) 
trinunionboodt (trin-u'nyon-hud), n. [< trin- 
union + -hood.} Triunity." [Rare.] 
Who (were it possible) art more compleate 
In Goodnesse than Thine owne Trin-vnionhood. 
Dames, Muse's Sacrifice, p. 82. (Dairies.) 
trio (tre'6 or tri'6), n. [= P. Sp. Pg. trio = G. 
Dan . Sw. trio, < It. trio, a musical composition 
in three parts, a trio, glee, < L. tres, neut. tria, 
three: see three.} 1. In music, a composition or 
movement for three solo parts, either vocal or 
instrumental, usually without accompaniment. 
Specifically, either (a) an instrumental work for three in- 
struments and planned like a quartet, or (b) a second or 
subordinate division of a minuet, scherzo, or march, usu- 
ally in a contrasted key and quieter in style, so as to be a 
foil to the principal division : so called because originally 
performed by a trio of instruments. 
2. A company of three vocalists or instrumen- 
talists who perform trios. 3. A group, com- 
bination, or association of three. 
The trio were well accustomed to act together, and were 
linked to each other by ties of mutual interest and advan- 
tage. Dickens, Old Curiosity Shop, 11. 
4. In the game of piquet, three aces, kings, 
queens, or knaves, held in one hand : a count- 
ing combination of cards, 
triobolart (tri-ob'o-lar), . [Also, erroneously, 
triobitlar; < L. triobdtus, < Gr. TpiA/Jofov, a three- 
obol piece, < rpcif (rp<-), three, + o/3o/tof, obol : 
see obol.} Of the value of three oboli ; hence, 
mean; worthless. 
A trivial and triobular author for knaves and fools, an 
image of idleness, an epitome of fantasticality, a mirror 
of vanity. G. Hartley, Four Letters. 
6484 
triobolaryt (hi-ob'o-la-ri), a. [As triobolar.} 
Same as triobolar. Hotrell, Letters, ii. 48. 
triocephalus (tri-o-sef'a-lus), n. [NL., irreg. 
for trii'iicephalux."} Same us tricnrcphalitx. 
trioctile (tri-ok'til), n. [< L. ires (tri-), three, 
+ octo, eight, + -He (uf.octilc).} In astral., an 
aspect of two planets, with regard to the earth, 
when they are three octants or eighth parts of 
a circle (that is, 135) distant from each other. 
triod (tri'od), n. [< Gr. Tpeit; (T/H-), three, + o66f, 
way.] A sponge-spicule of the triaxon or trira- 
diate type, having three equal rays; a three- 
way spicule. 
Triodia (trl-6'di-a), n. [NL. (R. Brown, 1810) ; 
named from the three-toothed flowering glume, 
< Gr. rpeii; (rpi-), three, + Motif, tooth.] A genus 
of grasses, of the tribe Festuceee, type of the sub- 
tribe Triodiese. It is characterized by panicled spike- 
lets of numerous flowers, the three-nerved flowering glume 
bearing three teeth or lobes, the middle tooth forming a 
cusp or awn. There are 26 species, natives of temperate and 
subtropical parts of Africa, Europe, Australia, New Zea- 
land, and America, in the last extending sparingly within 
the tropics. They are perennial grasses, often hard, rigid, 
and with a branching or stoloniferous base, bearing usually 
narrow, stiff, convolute leaves, sometimes tapering into a 
pungent point. The inflorescence is highly polymorphous, 
sometimes narrow and composed of but few spikelets, or 
ample and dense, or lax and spreading, with weak, elon- 
gated filiform branchlets. The former genera Uralepi* 
(Nuttall, 1817) and Trieuspis and Triplasis (both of Beau- 
vois, 1812) are now included in this. T. cuprea, known 
as full redtop, is an ornamental grass of sandy places 
from New York south ward, with a large compound panicle, 
sometimes a foot broad, bearing very numerous shining 
purple spikelets. For T. purpurea, a small species re- 
markable for its acid taste, see sand-grass, 2. Three other 
species occur on the Atlantic coast in Florida or north- 
ward. For T. decumbent, see heather-gran. 
Triodion (tri-6'di-on), . [MGr. rpi^iov, < rpeic 
(rpt-), three, + 6<S<if, way.] An office-book of 
the Greek Church, containing the offices from 
the Sunday before Septuagesima to Easter eve. 
Triodites (tri-o-di'tez), n. [NL. (Osten-Sacken, 
1877), < Gr. TpioS'tTiif, one who frequents cross- 
roads, a street-lounger, also common, vulgar, < 
rpiodof, also rpiodia, a meeting of three roads: 
see triad.} A genus of bee-flies, of the dip- 
terous family Bombt/liidss. They have the appear- 
ance of an elongated Anthrax, but the eyes of the male are 
Triodites mus, female. 
contiguous for a short distance on the vertex. The only 
known species, T. mus, of the western United States, is a 
notable insect in that its larva is a voracious feeder on 
the eggs of the short-horned grasshoppers, including the 
destructive Rocky Mountain locust, Melanoplus spretus. 
Triodon (tii'o-don), n. [NL. (Cuvier, 1829), < 
Gr. Tpcif (rpt-j, three, + bfovf = E. tootJi.} 1. A 
genus of plectognath fishes, typical of the fam- 
ily Triodontidee. 2. [?. c.] A member of this 
genus. 
Triodontidee (tri-o-don'ti-de), n. pi. [NL., < 
Triodon(t-) + -idee.] A family of gymnodont 
plectognaths, typified by the genus Triodon. 
They have an extensive abdominal fold of skin like a dew- 
lap, and rhombiform scales ; the upper jaw is divided by 
a median suture, but the under jaw is undivided, the two 
jaws thus giving the appearance of three teeth (whence 
the name). Also Triodontes, Triodontoictei, Triodontoidea. 
triodontoid (tri-o-don'toid), a. and n. I. a. Of 
or pertaining to the Triodontidse. 
II. n. A triodon, or any member of the above 
group. 
Tricecia (tii-e'shia), n.pl. [NL., < Gr. rpeif (rpt-), 
three, + okof , house.] The third order of plants 
in the class Polygamia, in the Linnean system. 
It comprises plants with unisexual and bisexual flowers on 
three separate plants, or having flowers with stamens only 
on one, pistils on another, and bisexual flowers on a third. 
The fig-tree and fan-palm (Chameerops) are examples. 
tricecious(tri-e'shus), a. [<Gr. TpeZf (rp*-), three, 
-f- okof, house.] In hot., having male, female, 
and hermaphrodite flowers, each on different 
plants ; pertaining to the order Trieecia. 
trireciously (tri-e'shus-li), adv. In a trioacious 
manner. 
trioicOUS (tri-oi'kus), a. In bot., same as trice- 
cious. 
Triopidae 
triole (tre'61), H. [Dim. of trio; cf. triolet.} In 
music, same as triplet. 
Is called a triole, and means that the three notes are to 
be played in the time of [two]. 
,S'. Lanier, Science of Eng. Verse, p. 108. 
trioiein (tri-6'le-in), . [< L. tres ((n'-), three, 
+ E. ole(ic) + -< 2 .] A glycerol ester contain- 
ing three oleic acid radicals. It is at ordinary 
temperatures a clear oily liquid, nearly colorless, and is 
the chief constituent of all fatty oils. 
triolet (tre'o-let), n. [< F. MoM, :i triolet, OF. 
triolet, a triolet, also trefoil, < It. trio, three : see 
trio.} 1. A poem in fixed form, borrowed from 
the French , and allied to the rondel and rondeau . 
It consists of eight lines on two rimes, and is generally 
written in short measures. The first pair of lines are re- 
peated as the seventh and eighth, while the first is repeated 
as the fourth. Representing the repeated lines by capital 
letters the rime-scheme would thus be A, B, a, A, a, b, 
A, B. In humorous examples a fresh sense is often skil- 
fully given to the fourth line. The tirst French triolet is 
said to have been by Adam le Roi (end of thirteenth cen- 
tury). Triolets were written in England as early as 1651 by 
Patrick Carey, whose efforts Sir Walter Scott published 
in 1820. 
2. Ill mimic, same as triplet. 
trional (tri'o-nal),. A synthetic remedy used 
as a hypnotic. [Recent.] 
Triones (tri-6'nez), n. pi. [NL., < L. triones, the 
plowing-oxen : see Septentrion.} In astron., a 
name sometimes given to the seven principal 
stars in the constellation Ursa Major, popularly 
called Charles's Wain. 
Trionychidae (tri-o-nik'i-de), . pi. [NL., < Tri- 
onyx (-onycli-) + -idee.} A family of turtles, typ- 
ified by the genus Trionyjr; soft-shelled turtles. 
This family, though not a large one, is an old type, repre- 
sented from the Cretaceous period onward, and at the pres- 
ent day by several generic typea of the warmer waters of 
both hemispheres, being thus very widely distributed. The 
body is very flat and subcircular or disk-like, and covered 
with soft, tough integument instead of a shell ; the skin is 
variously roughened or tuberculous in different cases; the 
feet are clubbed, webbed, and formed for swimming, and 
end in three claws; the neck is long, and the snout is 
sharp. These turtles are entirely aquatic, and live in 
ponds, where they usually lie half buried in the mud. 
They are chiefly carnivorous, highly predaceous and fero- 
cious, and bite severely. The flesh of some species is 
highly esteemed. The largest living soft-shelled turtle 
is Chitra indica, sometimes taken as type of a different 
family. (See Chitra, Chitradse.) Several American forms 
occur in the United States, as Trimiyx (or Aspidonectes) 
ferox, the southern soft-shelled turtle, of the lower Missis- 
sippi and of other rivers flowing into the Gulf of Mexico, 
12 to 18 inches in length of body ; Agpidonectes spinifer, 
with several conical protuberances on the back (see cut 
under Aspidonectes); and Emyda mutica, a smaller spe- 
cies, up to 12 inches in length of carapace, inhabiting the 
middle and upper Mississippi region and some of the 
tributaries of the St. Lawrence river (see Emyda). Also, 
wrongly, Trionycidx. 
trionychoid (tri-on'i-koid), . Resembling or 
related to a turtle of the genus Trionyx; be- 
longing to the Trionychoidea. 
Trionychoidea (tri-on-i-koi'de-a), n.pl. [NL., 
< Trionyx (-oiiych-) + -oidca.} The Trionychi- 
dx regarded as a suborder of Chelonin, of equal 
rank with Athecse (the Sphargididse) and with 
Testudinata, 2, or Thecoph&ra (all other chelo- 
niaus). 
trionym (tri'o-nim), n. [< Gr. rpelf(Tpc-), three, 
+ &VV/M, name.] A name consisting of three 
terms; a trinomial name in zoology or botany; 
the name of a subspecies in the trinomial sys- 
tem of nomenclature. See trinomial, n., and 
trinomialism. Coves, The Auk, 1884, p. 321. 
trionymal (tri-on'i-mal), a. [< trionym + -al.} 
Of or pertaining to a trionym; trinomial. J. 
A. Allen, The Auk, 1884, p. 352. 
Trionyx (tri'o-niks), n. [NL. (Geoffroy St. 
Hilaire, 1809), < Gr. rpc'it; (rpt-), three, + ovuf 
(bvvx-), a nail: see onyx.} A genus of soft- 
shelled turtles, typical of the Trionychidee : in- 
exactly synonymous with Aspidonectes. It is 
so called from the three claws in which the 
webbed feet end. See Trionychidse. 
Triopa (tri'o-pa), n. [NL. (Johnston), < Gr. 
rpeif (rpi-), three, + 0717, opening, hole.] The 
Clubbed Dorid (TV 
typical genus of Triopidee, having a row of 
clubbed processes along each side of the man- 
tle, as T. clariger. 
Triopidae (tri-p'p'i-de), n. pi. [NL., < Triopa + 
-idee.} A family of nudibranch gastropods, typ- 
ified by the genus Triopa; the clubbed dorids, 
having slightly hooked teeth in very numerous 
