/ Dictionary / Index I indecl.: Meaning and Definition of Find definitions for: indecl. Pronunciation: [key] indeclinable. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. indecisive indeclinable 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