invasion, n. irruption, [foray], [raid], aggression; [violation], [infringement], [encroachment], [intrenchment].

inveigle, v. [wheedle], [seduce].

inveiglement, n. [wheedling], [seduction].

investigate, v. [probe], [sift], [examine].

investigation, n. [examination], [inquiry], research.

invidious, a. [objectionable], [offensive].

invincible, a. indomitable, [unconquerable].

invisible, a. imperceptible, microscopic, evanescent.

invitation, n. [bidding], [call], summons.

invite, v. [bid], [ask], summon; [allure], induce, [entice].