invaginate 
ruijiiin, a glieath : ee mi/ina.] To sheathe ; 
insert or receive as into a sheath; introvert: 
opposed In ( r/ii/iimt< . 
Dr. Kingsley claims that thi: ronipoiinil ryo arisen as un 
invayiiutted pitof ectuiltTm. Anfr. Satiindixt, XXI. 1120. 
invagination (in-vaj-i-nfi'shon), w. [< /- 
rdijniiili + -inn.] Tin' (tc't Mt 1 introverting or 
sheathing, or the state of being sheathed; in- 
sertion or reception as into a sheath ; intus- 
susception. 
invalescence 1 t (iu-va-les'ens), . [< L. '- 
priv. + v<ili'm;r)i(t-)ti, ppr. of valettccre, grow 
strong. Of. convalescence.] Lack of health. 
Jollll.lOII. 
invalescence'-'t (in-va-les'ens), n. [< L. inva- 
li fiTre, become strong, <. in- intensive + vales- 
cere, inceptive of valere, be strong: see valid. 
Cf. convalescence.'} Strength ; health. Iluiley, 
1731. 
invaletudinaryt (iii-val-e-tu'di-na-ri), a. [= 
F. invaletudinaire = Sp. ini'alitudiitario, < L. 
invalt'litdiiinriiiK, sick (used only as a noun), < 
in- intensive + raletudinariiis, sick: see vale- 
tutli>mry.~] Sick; ill; valetudinary. 
Whether usually the most Btudious, laborious ministers 
be not tile most invaletudinary and innrm ? 
Paper* between the C<im)ni&fionem for Review of the Liturgy 
[(1861), p. 127. 
invalid 1 (in-val'id), o. [= P. invalide = Sp. 
invdlido = Pg. It. invalido, < L. invalidiis, not 
strong, weak, inefficient, \ in- priv. + validus, 
strong: see valid. Cf. invalid 2 .'] 1. Not valid; 
of no force, weight, or cogency ; weak. 
But this I urge, 
Admitting motion in the heavens, to show 
Invalid that which thee to doubt it moved. 
Milton, V. L., Till. 118. 
The greater our obligations to such writers, the more 
desirable is it that their iniitlbl Judgments should be dis- 
criminated from their valid. F. Hall, False Philol., p. 2. 
2. In late, having no validity or binding force ; 
wanting efficacy; null; void: as, an invalid 
contract or agreement. 
invalid 2 (in'va-lid or -led), a. and n. [Formerly 
also invalide; = D. inraliede, a., = G. invalide = 
Dan. Sw. invalid, u., < F. invalide (= Sp. invdlido 
= Pg. It. invalido), a., not strong, sick, invalid; 
as a noun, a disabled soldier; < L. invalidus, 
not strong: see invalid 1 ."] I. a. Deficient in 
health; infirm; weak; sick. 
II. n. 1 . An infirm or sickly person ; one 
who is affected by disease or disabled by 
any infirmity. Hence 2. Something that is 
damaged, or the worse for wear, but not so 
much as to be wholly unserviceable. [Humor- 
ous.] 
The carriages were old second-class iiintliil* of English 
lines : but they were luxurious enough after the long 
journey in dust and sun. 
W. a. Russett, Diary in India, I. 158. 
invalid 2 (in'va-lid or -led), v. [< invalid^, a.] I, 
trans. 1. To affect with disease ; render an in- 
valid: chiefly in the past participle. 
Mr. Pickwick cut the matter short by drawing the in- 
valided stroller's arm through his, and leading him away. 
Dickens, Pickwick, xlv. 
Rheumatics, who so largely preponderate among the in- 
valided visitors at our sulphur springs. 
Harper's Mag., LXIX. 43tf. 
2. To register as an invalid; enroll on the list 
of invalids in the military or naval service; 
give leave of absence from duty on account of 
ill health. 
II. intrans. To cause one's self to be regis- 
tered as an invalid. [Rare.] 
He hud been long suffering from the insidious attacks 
of a hot climate, and though repeatedly advised to invalid, 
he never would consent. Marryat, Peter Simple. 
invalidate (in-val'i-dat), v. t. ; pret. and pp. 
iiinilitliilcd, ppr. invalidating. [< ML. *invali- 
(iatits, pp. of "invaUdare (> It. invalidarc = Sp. 
Pg. invalidar = F. invalider), make invalid, < L. 
iurulidtta, invalid: see invalid 1 . Cf. validate."] 
1. To render invalid; destroy the strength or 
validity of; render of no force or effect. 
Argument is to be invalidated, only by argument, and 
is in itself of the game force, whether or not it convinces 
him by whom it is proposed. Jnhnson, Rambler, No. 14. 
The force of the objection above set forth may be fully 
admitted, without in any degree invalidating the theory. 
II. Spencer, Social Statics, p. 41. 
Specifically 2. In law, to deprive of binding 
force or legal efficacy: as, fraud iiu-<ilidtit<'x a 
contract. 
invalidation (in-val-i-da'shon), n. [< F. in- 
riilidatioii = Sp. invalidiirinii ; us inralidnti + 
-ion."] The act of invalidating or of rendering 
invalid. 
3169 
The thirty-four confirmations (of Magna Charta) would 
have been only so many repetitions of their absurdity, sit 
many new links in the chain, and so m&ny invalidations 
of their i i(;lit. 
llurke, Powers of Juries in Prosecutions for Libels. 
invalidet, a. and . An obsolete form of in- 
valitl-. 
invalidhood (iu'va-lid- or-led-hud), . [< in- 
valid- + -hood.] r rhe state of being an invalid; 
iuvalidism. [Rare.] 
About twenty years ago she had an illness, and, on the 
strength of it, has kept up a character for inaalidhnod ever 
since. /' Broughton, Red as a Rose is She, i \. 
invalidism (in'va-lid- or -led-izm), n. [< in- 
vaUd"* + -ism."] The condition of being an in- 
valid; a state of debility or infirmity; espe- 
cially, a chronic condition of poor health. 
Inoalidurm is a function to which certain persons are 
horn, as others are born to poetry' or art as their calling. 
O. W. Holmes, Old Vol. of Life, p. 109. 
invalidity (in-va-lid'i-ti), n. [= P. invalidity 
= Pg. invalidade = ft. iui-<itt<tiiu. invalidity, < 
ML. invalidita(t-)s, weakness, infirmity (from a 
wound), < L. invalidity, not strong: see invalid 1 , 
invalid^.] If. Weakness; infirmity. 
He ordered that none who could work should be Idle ; 
and that none who could not work, by age, sickness, or 
invalidity, should want. Sir W. Temple. 
2. Lack of validity ; want of cogency, force, or 
efficacy; specifically, lack of legal force: as, 
the invalidity of an argument or of a will. 
But, however, to prevent all cavillings, In this place 
lie shew the invalitltty of this objection. 
GlanmUe, Pre-existence of Souls, IT. 
The penalty of invalidity attaching to unstamped docu- 
ments of various kinds has proved a very effective deter- 
rent to evasion. Encyc. Brit., XX III. 88. 
invalidly (in-val'id-li), adv. So as to be in- 
valid ; without validity. 
Fraudulently bought, and therefore invalidly obtained. 
Philadelphia Times, Oct. 26, 1885. 
invalidness (in-val'id-nes), n. Invalidity: as, 
the invalidness of reasoning. [Rare.] 
invalorous(in-val'o-rus),o. [<in-3 + valorous."] 
Not valorous; cowardly. D. ff Council. 
invaluable (in-val'u-a-bl), a. [< JM-3 + valit- 
able."] Above or beyond valuation ; too valu- 
able for exact estimate ; inestimable. 
The ancient amity <fe friendship betweene both our lands, 
with the inualuable commodity of sweet amiable peace. 
Uakluyt'e Voyages, I. 160. 
There was an invaluable shrine for the head of St. John 
the Baptist, whose bones and another of his heads are in 
the cathedral at Genoa. 
R. Curzon, Monast. in the Levant, p. 863. 
invaluableness (in - val ' u - a - bl - nes), . The 
character of being invaluable. 
Deny, if th.ui canst, the invaluablenesse of this heavenly 
gift Bp. Hall, Satan's Fiery Darts, U. 
invaluably (in-val'u-a-bli), adv. Inestimably. 
That in ml mi hi I/ precious blood of the Sonne of God. 
Bp. Hull. Sermon of Thanksgiving, Jan., 1625. 
invaluedt (iu-val'ud), a. [< in-S + valued."] In- 
estimable; invaluable. 
The monument of worth, the angel's pleasure, 
Which hoardeth glory's rich invalu'd treasure. 
Ford, Fame's Memorial, Epitaphs. 
invariability (in-va'ri-a-bil'i-ti), n. [= F. in- 
variabilite = Sp. ini-aridbilidad = Pg. invaria- 
bilidade = lt.invariabilita ; - aeinvariable + -ity."] 
Lack of variability or of liability to change ; m- 
variableness. 
Therfore, this invariabilita in the birds' operations must 
proceed from a higher intellect. 
Sir K. Digby, Of Bodies, xxxvii. 
invariable (in-va'ri-a-bl), a. and n. [= P. t- 
variable = Sp. invariable = Pg. invariavel = It. 
invariabile; as in- 3 + variable.'] I. a. 1. Not 
variable ; constant ; uniform ; unchanging. 
If taste has no fixed principles, if the imagination is not 
affected according to some invariable and certain laws, our 
labour is like to be employed to very little purpose. 
Burke, On Taste, Int. 
The only evidence of the shells having been naturally 
left by the sea consists in their invariable and uniform ap- 
pearance of extreme antiquity. 
Darwin, Geol. Observations, ii. 242. 
2. Not capable of being varied; unalterable; 
unchangeable.- invariable antecedent, in logic. 
See antecedent, 3 (c). Invariable pendulum, a pendu- 
lum constructed to be transported unchanged from one 
station to another, in order to determine the relative ac- 
celeration of gravity. Such a pendulum swings upon a 
knife-edge (which see). Invariable system, in dynam., 
a system of points whose relative distances remain con- 
stant. 
II. n. In math., a quantity that does not 
vary ; a constant. 
invariableness (in-va'ri-a-bl-nes), n. The 
state of being invariable; constancy of state, 
condition, or quality; immutability; unchange- 
ableuess. 
invecked 
A variety of dispensations [may] be consistent with an 
invariableness of design. 
A. Tucker, Light of Nature, II. ill. -J4. 
invariably (in-va'ri-u-bli). <nlr. In an invari- 
able manner; without alteration or change; 
constantly; uniformly. 
It |time| Is conceived by way of substance, or Imagined 
to subsist of itself, independently and invariably, us all 
abstract ideas are. Law, Enquiry, Of Time, U. 
Death succeeds life Inevitably and invariably. 
J. F. Clarke, Self-Culture, p. 187. 
invariance (iu-va'ri-ans), w. [< invarian(t) + 
-cr.~] In math., the essential character of in- 
variants; persistence after linear transforma- 
tion. 
invariant (iu-va'ri-ant), a. and . [< in-8 + 
nn-iaiit.'] I. . Not varying or changing; re- 
maining always the same. 
However variable the visible antecedents may be, the 
real determinants the cooperant factors are in each 
case invari<iiitn. 
<]. H. Lewes, Probs. of Life and Mind, II. in. 
II. n. In math., a function of the coefficients 
of a quantic such that, if the quantic is linear- 
ly transformed, the same function of the new 
coefficients is equal to the first function multi- 
plied by some power of the modulus of trans- 
formation. -Absolute, differential, skew, etc., in- 
variant. See the adjectives. Theory Of Invariants, 
a branch of mathematics which studies the fundamental 
invariants of qualities. 
invariantive (in-va'ri-an-tiv), a. [< invariant 
+ -ice.] Pertaining to an invariant; persist- 
ing after a linear transformation. 
A curve u = o may have some invariantiee property, 
viz. a property independent of the particular axes of co- 
ordinates used in the representation of the curve by its 
equation. Encyc. Brit., VI. 722. 
invaried (in-va'rid), a. [<- 3 + varied.] Un- 
varied ; not changing or altering. [Rare.] 
Change of the particles, or the lesser invaried words, 
that add to the signification of nouns and verbs. 
Blackball, Sacred Classlcks, I. 136. 
invariod (in-va'ri-od), n. . [L., < in- priv. + 
variare, vary, + term, -od, < Gr. Mrff, a path.] 
In math., an ultracritical function. 
Sir James Cockle suggests that ... it may be possible 
by means of semicritlcal relations to form invariods, that 
is, ultra-critical functions of the calculus analogous to the 
Invariants or ultra-critical functions of algebra. 
. Harley, Proc. Roy. Soc., XXXVIII. 57. 
invasion (in-va'zhon), w. [= F. invasion = Pr. 
entasio = Sp. invasion = Pg. invasSo = It. in- 
rasione, < LL. inrasio(n-), an attack, invasion, < 
Ij.invadere, pp. invasus, invade: see invade.] 1. 
The act of invading a country or territory as an 
enemy; hostile entrance or intrusion. 
We made an invasion upon the south of the Cherethites. 
1 Sam. xxx. 14. 
No Mahratta invasion had ever spread through the prov- 
ince such dismay as this inroad of English lawyers. 
Macatday, Warren Hastings. 
Hence 2. A harmful incursion of any kind; 
an onset or attack, as of disease. 
What demonstrates the plague to he endemial to Egypt 
is its inraxitin and going off at certain seasons. Arbuthnot. 
The invaxiun of the symptoms [in smallpox] is sudden 
and severe. Encyc. Brit., XXIL 163. 
3. Infringement by intrusion ; encroachment 
by entering into or taking away what belongs 
to another: as, an invasion of one's retirement 
or rights. 
Here is no invasion and conquest of the weaker nature 
by the stronger, but an equal league of souls, each in Its 
own realm still sovereign. 
Lowell, Among my Books, 1st ser., p. 329. 
invasive (in-va'siv), a. [= F. im-asif= Sp. Pg. 
It. invasivo, < ML. invasirus, invasive, < L. inva- 
sus, pp. of invadere, invade : see invade.] Tend- 
ing to invade ; characterized by invasion ; ag- 
gressive. 
Prohibited by the magistrates and rulers to vse or 
weare any weapon, either inwuiee or defensiue. 
Hatt, Hen. VI., an. 34. 
He [Washington] had such admirable self-command 
that he was not at all invasive of the opinion of others. 
Theodore Parker, Historic Americans, p. 129. 
invassalt (in-vas'al), v. t. [< i-2 + vassal.] 
Same as enrassal, 
Whilst I myself was free 
From that intolerable misery 
Whereto affection now invassels me. 
Daniel, Queen's Arcadia, U. 1. 
invecked (in^vekt').. [Also envecked; cf. '- 
vected, inreied.] Bordered exteriorly by small 
rounded lobes of slight projection as'compared 
with their width ; invected. 
The eastern window [of Whalley Church] ... is invecked 
with ramified tracery. Baines, Hist Lancashire, II. 7. 
It has no sleeves, but reveals an under coat of pale blue 
with imecked edges. N. and Q., 7th ser., VII. 7. 
