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definitions

in-

1

a prefix representing English in (income; indwelling; inland, etc.), but used also as a verb-formative with transitive, intensive, or sometimes little apparent force (intrust; inweave, etc.). It often assumes the same forms as in-2, such as en-1, em-1, im-3.

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Nearby words

in wait, in waiting, in with, be, in your face, in't, in-, in-and-in, in-and-out, in-and-out bond, in-and-outer, in-basket

Origin of in-

1
Middle English, Old English; see in

Definition for in- (2 of 3)

in-

2

a prefix of Latin origin meaning primarily “in,” but used also as a verb-formative with the same force as in-1 (incarcerate; incantation).
Also il-, im-, ir-.
Compare em-1, en-1.

Origin of in-

2
< Latin, combining form of in (preposition); cognate with in

Definition for in- (3 of 3)

in-

3

a prefix of Latin origin, corresponding to English un-, having a negative or privative force, freely used as an English formative, especially of adjectives and their derivatives and of nouns (inattention; indefensible; inexpensive; inorganic; invariable). It assumes the same phonetic phases as in-2 (impartial; immeasurable; illiterate; irregular, etc.). In French, it became en- and thus occurs unfelt in such words as enemy (French ennemi, Latin inimicus, lit., not friendly).
Also il-, im-, ir-.

Origin of in-

3
< Latin; akin to an-1, a-6, un-1

Synonym study

The prefixes in- and un- may both have, among other uses, a negative force. In- is the form derived from Latin, and is therefore used in learned words or in words derived from Latin or (rarely) Greek: inaccessible, inaccuracy, inadequate, etc. Un- is the native form going back to Old English, used in words of native origin, and sometimes used in combination with words of other origins if these words are in common use: unloving, ungodly, unfeeling, unnecessary, unsafe.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for in- (1 of 2)

in-

1

il-, im- or ir-

prefix

not; non-incredible; insincere; illegal; imperfect; irregular Compare un- 1

Word Origin for in-

from Latin in-; related to ne-, nōn not

British Dictionary definitions for in- (2 of 2)

in-

2

il-, im- or ir-

prefix

in; into; towards; within; oninfiltrate; immigrate
having an intensive or causative functioninflame; imperil

Word Origin for in-

from in (prep, adv)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012