/ Dictionary / Index I illin': Meaning and Definition of Find definitions for: ill•in' Pronunciation: (il'in), [key] foolish; crazy (used esp. in the phrase be illin'&hasp;). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. illimitable ill-informed Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language