opisthotic 
or pertaining to the opisthotic : correlated with 
cpiotir, iiriiiific, anil pti-i-ntif. Scr ntic. 
In existing Ainphilila, a protitic omification appears to 
he very constant. Tin- oomtant existence of dlsunctopo- 
llmtic anil opiutio elements is ilmililfnl. 
lluxley, Anat. Vert., p. 152. 
II. . The postero-inforior potrosal bone; 
ono of tin' otic elements, the posterior and in- 
terior ossification of the periotic capsule, which 
contains the essential auditory apparatus, form- 
in;; a part of the petronl or petroinastoid bone. 
SIM' cuts under Crocodilia and AW. 
opisthotonic (o-pis-tho-ton'ik), ti. [< Or. cnrin- 
floToviKw;, pertaining to opisthotonos, < mufiu- 
rovof, opisthotonos: see 0pfeA0*MOf.1 Of or 
pertaining to opisthotonos; characterized by, 
resulting from, or exhibiting opisthotonos. 
The aputholenic attitude was maintained even during 
, lt) ep. * Lancet, No. 8440, p. 207. 
opisthotonos, opisthotonus (op-is-thot'o-nos, 
-mis), H. [L., <Qr. fcnoMrOMCi &lso uxtnOnrovia, 
a disease in which the limbs are drawn back, < 
omoOArovos, drawn back, < faicOfv, behind, back, 
+ reivtiv, stretch.] A tonic spasm in which the 
body is bent backward. DumjlisoH. 
opisthural (o-pis'thu-ral), a. [< opisthure 
-/.] Of or pertaining to the opisthure. J. A. 
Hi/il< r. Compare f'li/inil, liypunil. 
opisthure (6-pis'thur), n. [< Gr. birinOcv, behind, 
+ oi'pa, the'tail. ] The posterior end of the cau- 
dal axis of certain fishes and embryos of fishes, 
which degenerates into a rudimentary organ, or 
becomes absorbed in the permanent caudal fin 
developed in front of it. ./. A. Kyder. 
opium (6'pi-um), n. [In ME. opic, opye, < OF. 
opic, (see opie) ; F. opium = Sp. Pg. opio = It. 
oppio = D. G. Sw. Dan. opium, < L. opium, opion 
(cf. Bulg. afion. ofion = Serv. ajijun, < Turk. 
nfi/iiii. = Pers. ifyun = Hind, apliim, a fun, afyiin, 
< AT. afyiin), ^ Gr. kmav, poppy-juice, opium, < 
oirof, juice, i. e. vegetable juice, sap.] The in- 
spissated juice of I'apaver somiiifcrum, a poppy 
cultivated from early antiquity for the sake 
of this product. See poppy and I'aparcr. The 
opium exudes as a.milky juice from shallow incisions 
made in the partly ripened capsules or heads still on the 
plant. It soon thickens, is collected by scraping, and 
kneaded into a homogeneous mass, forming then a red- 
dish-brown sticky gum-like substance of bitter taste and 
peculiar odor. Opium was known to the Greeks, but was 
not much used l>efore the seventeenth century; at present 
it is the most important of all medicines, and its applica- 
tions the most multifarious, the chief of them being for 
the relief of pain and the production of sleep. Its ha- 
bitual use is disastrous and difficult to break up. It is 
classed as a stimulant narcotic, acting almost exclusively 
on the central nervous system when taken internally; in 
large quantities it is a powerful narcotic poison, resulting 
in a coma characterized by great contraction of the pu- 
pils, insensibility, and death. The chief active principle 
of opium is morphia, but it also contains at least sixteen 
other alkaloids, some of which have similar properties. 
(See narcotine.) Though opium can be produced in Eu- 
rope, the United States, etc., its commercial production 
is limited to countries where labor is cheap and the drug 
in common nse, namely Turkey, Persia, Egypt, India, and 
China. The Western market is supplied largely from Asia 
Minor. The Indian export goes chiefly to China. 
Sleep hath forsook and given me o'er 
To death's benumming opium as my only cure. 
Mil i" a, S. A., L 630. 
India opium opium produced in India. Opium joint. 
See >>i(, n., 4. Tincture of opium, the alcoholic solu- 
tion of opium. Vinegar of opium. Same as blade-drop. 
opium-eater (6'pi-um-e*ter), . One" who ha- 
bitually uses opium in some form as a stimulant. 
opium-habit (o'pi-um-habit), H. The habitual 
use of opium or morphine as a stimulant. See 
niorpliioHiniiiii. 
opium-liniment (6'pi-um-lin"i-ment), . Soap- 
Uniment and laudanum. Also called ONOdyiW 
liniment. 
opium-plaster (6'pi-um-plas'tev), w. Lead- 
plaster and Burgundy pitch with C per cent, of 
extract of opium ; the emplastrum opii of the 
United States and British Pharmacopoeias. 
Opio-. An incorrect form sometimes used for 
flinilit- in compound words. 
opobalsam (op-o-bal'sam), . [= F. opobal- 
xiimr, OpohUMMMM = Sp. opobdlgttmo = Pg. It. 
opobalxamo, < LL. opobalsam inn, < Gr. 6;ro/9<iA- 
oa/iov, the juice of the balsam-tree, < curoc, juice, 
+ ,ia?.aafiov, balsam: see MMMkl A resinous 
juice, also called balm or balsam of (Ulead. See 
h<ilni, 
opobalsamum(op-o-barsa-mum), n. [LL.: see 
oiiobalMim.] Same as ovoboigam. Jer. Taylor, 
orks (ed. 1835), II. 119. 
4129 
ment; a solution of soap in alcohol witli tin- 
addition of camphor and essential oils: hence 
Miiiu-liini-s called xoap-liiiiwi ni. 
Opomyza (op-o-mi'/ii), . [NL. (Fallen, 1820), 
prob. < Gr. &*, f , nsprct, + in-iii, a lly (con- 
fused with /"Cm-, suck).] The typical genus 
of Oponn/zidti: It comprises small, somewhat linear 
flics of a yellowish color, often with spotted wingx, found 
In meadow-grass. About 20 European and 1 North Amer- 
ican species are known. 
oppilation 
hath a bag under her belly, "lit nf which Mir will li-t forth 
Ii,-r yi.inig OHMS and take them in again at her pleasure. 
The other is tin- Hying Sqiierrll. 
S. Clarke, Four Plantations in America (1670X p. 14. 
The potman is found no where but in America. He is 
the wonder of all the land animals 
J. Lav-am, History of Carolina, p. 198. 
2. A name of sundry other marsupials: a. il- 
ursine optimum (that is, the ursine dasyiin-); the 
vulpiiK 1 iijinxifiiin (the vulpine phmlmgift). 
dpomyzidie r (o K pTmi i '/i^e),. J ,. [NL., < Opo- opossum-mouse (o-pos'um-mous) A v-rv 
^K^hHfdi.] Asmallfamilvof ,V*rfdeaca- small marsupial mammal of Australia, A*ro- 
. , , it - n .._ bates pygm<fus; the pygmy petaurint, one 
the flying-plialangers. See Acrobates. 
opossum-shrew (o-pos'um-shrfi), n. An insec- 
tivorous mammal of the genus MMOdM. 
opossum-shrimp (o-pos'um-shrimp), . A Bern 
zopodous crustacean or shrimp of the family 
, represented by the genus Opomyza. 
Opont, prep. A Middle English form of upon. 
opononet, adr. A Middle Knglish fonn of upon- 
OHt'. 
opopanax (o-pop'a-naks), . [= F. opoponax, 
< L. opopanax, < <5r. cmoirdvaf, the juice of the 
plant jravaf, < omJc. juice, + ndvaf (also rravaxtf, 
neut. of 7rara/rf/c, all-healing), a plant: see pan- 
acea.] 1 . A gum-resin consisting of a concreted 
juice obtained from the roots of a plant of the 
genus l)}io}iitx (see def. 2). It is employed in per- 
fumery, and was long esteemed in medicine as sii anti- 
spasmodic, etc., but Is now little used except in the East 
Ladanum, aspalathum, opoponax, oananthe. 
B. Jonton, Cynthia's Revels, v. 2. 
2. [cap.] [NL. (Koch, 1825).] A genus of um- 
belliferous plants of the tribe I'eucedanea;, 
characterized by fruit with many oil-tubes and 
thickened margins, and by the absence of calyx- 
teeth. There are 2 or 3 species, of southern Europe and 
the Orient. They are perennial herbs with pinnate leaves 
and compound umbels with few small bracts and yellow 
flowers. 0. Chironium is the source of the drug opopanax. 
See Hemilei't allheal, under Hercules. 
oporice (o-por'i-se), . [L.,< Gr. oKupiKfi, fern. of 
oxupindf, made of fruit, < a-aitpa, dial. Mpr/, mapa, 
the end of summer, or early autumn, also the 
fruits of autumn.] A medicine prepared from 
several autumnal fruits, particularly quinces, 
pomegranates, etc., and wine, formerly used in 
dysentery, diseases of the stomach, etc. 
oporopolistt (op-o-rop'o-list), n. [< Gr. OTO- 
, a fruiterer, < oTii/xz, fruits of autumn, 
+ Trufclv, sell.] A'fruit-seller; a fruiterer. 
A certain man stood at a fruiterer's stall, or opwopolwt't, 
if you 'd have it in Greek. 
Bailey, tr. of Colloquies of Erasmus, I. 429. 
opossum (o-pos'um), n. [Formerly also opas- 
som; also.'and still in rural use, abbr. possum, 
formerly possowne; Amer. Ind.] 1. An Ameri- 
can marsupial mammal of the family Didel- 
pln/ida! (which see for technical characters). 
They have the four kinds of teeth which carnivorous quad- 
rupeds regularly possess (Incisors, canines, premolars, and 
molars)^ and are omnivorous, eating flesh and carrion, rep- 
tiles, insects, and fruits. The head is conical, and the snout 
somewhat resembles that of a pig ; the ears are large, leafy, 
and rounded; the 
eyes are small ; the 
whiskers are long; 
the legs are of pro- 
portionate length ; 
both fore and hind 
paws are five-toed, 
fashioned 
Opossum-shrimp (Mytis iHixta). 
Myaidce: so called because the females carry 
their eggs in pouches between the thoracic legs. 
See Myxis. 
opoterbdont (o-pot'e-ro-dont), a. and . I. a. 
Of or pertaining to the Opotcrodonta. 
II n. One of the Opoterodonta. 
Opoterodonta, Opoterodontia (o-pot'e-ro- 
don'tii, -shi-a), n. pi. [NL., prop. Hopotero- 
rfonta','etc., <'Gr. Mrepof, either, + oooi'f (Movr-) 
= E. tooth.] A suborder of OpJiidia, contain- 
ing angiostomatous or scolecophidian serpents 
of small size and resembling worms, having a 
contracted non-distensible mouth and imper- 
fect vision. The opisthotic bone is intercalated in the 
cranial walls, the palatines Ixnind the choame behind, the 
ethmoturbinals partly roof over the mouth, the maxillary 
bone is vertical and free, and there are no ectoptcrygcms 
and no pubes. The suborder is conterminous with the 
family TypMopidte, and U also called Kpanodania. Sec 
\ 
Common Opossum (Di&tphys 
like 
hands, especially 
the hind ones, 
which have an op- 
posable thumb ; 
and the tail is gen- 
erally long, scaly, 
and prehensile, so 
that the animal can 
hang by it The 
pelage is coarse ; 
the body is stout, 
and in size ranges 
from that of a large 
cat to that of a 
small rat Moet 
female opossums 
have on the belly a 
pouch containing 
the tents, into 
which the young 
are received as soon as they are born. They are born ex- 
tremely small and imperfect. The Virginia opossum has 
13 teats, and no doubt may have as many young at a birth, 
but the number is usually less. Opossums arc nocturnal 
animals ; they move on the ground rather slowly and awk- 
wardly, but are more at home in trees, and some of the spe- 
cies are aquatic. TJiough they are uncleanly, the flesh is 
white and palatable, especially in the autumn, when they 
feed much on fruits, and become as fat as pigs. They com- 
monly appear stupid, and in confinement continue sullen 
ami intractable. When caught or threatened with danger 
they feign death, and will submit to the must brutal mal- 
treatment without showing a sign of animation, whence the 
proverbial expression " to play possum. " Most opossums 
belong to the genus Didelvhys, ranging from middle lati- 
tudes in the Vnited states through the greater part of South 
America. The commonest and best-known is D. ttwini- 
Op^eWocT^^dok)^ IMsoopodeldoc*; ^^^J^&i^^S^& 
= F. opodelaodt. opodeltocn ; appar. a made-up , M)S8 ii m s of South America fonn another genus, Cro- 
.1 t j *"i_ i i* : . . : . 1 1 j. ' 
\nmngst the Beasts in Virginia there are two kinds 
most strange. One of them is the Female Potsoime, which 
W 
name, perhaps based on Gr. oirof, juice.] If. 
A plaster said to him- boon invented by Min- 
di'rerus. 2. A saponaceous camphorated lini- 
oppidan (op'i-dan), a. and n. [< OF. o rf ... 
< L. oppidanu,i,'of or in a town, < oppidum, OL. 
oppedvm, a walled town, perhaps < ob, before, 
toward, + 'jjedum (cf. Pedvm, a town in Lati- 
um), country, = Gr. irlfov, a plain.] I. a. Per- 
taining to a town; town. 
The temporal governmentof Rome, and oppidan affairs. 
Swell, Letters, I. i. 38. 
II. " It. An inhabitant of a town. 
The oppidans, in the mean time, were not wanting to 
trouble us. A. Wood, Annals Univ. Oxford, an. 1528. 
2. At Eton College, a student who is not on the 
foundation, and who boards with one of themas- 
ters or with a private family in the town : dis- 
tinguished from a colleger. 
oppigneratet, oppignoratet (o-pig'ne-rat, -no- 
rat), r. t. [< L. oppigneratus (ML. also oppig- 
noratus), pp. of oppignerare (> F. oppignorer), 
pledge, pawn, < ob, before, +pigncrare, pledge: 
see pignerate.] To pledge; pawn. Bacon. 
oppigriorationt (o-pig-no-ra'shon), n. [< OF. 
oppignoration, < ML. as if *oppigiioratio(n~), < L. 
oppiunerare, pledge : szeoppignerate.} The act 
of pledging, or giving security ; a pawning. 
The form and manner of swearing ... by oppiynora- 
(ion or engaging of some good which we would not lose : 
as, " Our rejoicing in Christ," our salvation, God's help, Ac. 
Bp. Andrew, Sermons, V. 74. (Daniel.) 
oppilate (op'i-lat), r. t.; pret. andpp.o^nVo/crf, 
ppr. oppilating. [< L. oppilattts, pp. of oppil<tr<; 
stop up, < ob,' before, + pilare, ram down ; cf . 
Gr. JTIAEIV, compress, press down, felt.] To 
crowd together; fill with obstructions. Cock- 
cram. 
oppilation (op-i-la'shon), n. [= F. opilation = 
Sp. opilacion = Pg. opilafffo = It. OppOottotf, 
< LL. oppitatio(n-), < L. oppilare, stop up: see 
oppilate.] The act of filling or crowding to- 
gether; a stopping by redundant matter; ob- 
struction, particularly in the lower intestines; 
stoppage; constipation. 
These meagre, starved spirits who have half stopt the 
organs of their minds with earthy oppilations. 
B. Jnnton, Volpone, ii. 1. 
Gouts and dropsies, catarrhs and optiHationt. 
Jer. Taylor, Works (ed. 1836), I. CC4. 
And as he is who falls, and know s not how, 
By force of demons who to earth down drag him. 
Or other oppilation that binds man, . . . 
Such was that sinner after he had risen. 
LmgfcUoic, tr. of Dante's Inferno, xxiv. 114. 
