Il-, as in illegal. See In- (1).
In-, Im- (L.), not, as inconvenience, incautious, infirm. Before p the n changes to m, as impudent; before l, m, and r it is assimilated to those consonants, as illegal, immature, irregular. This prefix thus appears as en-, i-, il-, im-, in-, ir-, as enemy, ignoble, illegal, immortal, infirm, irregular. [L.; cog. with Gr. an-, Eng. un-.]
In- (L.), in, into, as infuse, illumine, impel, irrigate. It becomes il- before l; im- before b, m, and p; ir- before r. This prefix thus appears as am-, an-, em-, en-, il-, im-, in-, ir-, as ambush, anoint, embrace, enclose, illude, immure, include, irritate.
In- (A.S.), in, on, as income, inward, inland, insight; to make, as imbitter, lit. to put into a state of bitterness; as im- in imbed, impark, &c.
Inter- (L.), in the midst of, between, as interval, intellect, intermarry. [A compar. form; cog. with Eng. under, and Sans. antar, within.]
Intra- (L.), in the inside of, within, as intramural. [Contr. of intera, ablative feminine of interus, inward—Inter-.]
Intro- (L.), into, within, as introduce. [Contr. of intero, ablative masculine of interus—Inter-.]
Ir-, as in irritate. See In- (2).
Ir-, as in irregular. See In- (1).
Iss-, as in issue. See Ex- (1).