/ Dictionary / Index I irritability: Meaning and Definition of Find definitions for: ir•ri•ta•bil•i•ty Pronunciation: (ir"i-tu-bil'i-tē), [key] — pl. -ties. the quality or state of being irritable. the ability to be excited to a characteristic action or function by the application of some stimulus: Protoplasm displays irritability by responding to heat. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: irritability (Thesaurus) irriguous irritable Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language