/ Dictionary / Index H hyperirritability: Meaning and Definition of Find definitions for: hy•per•ir•ri•ta•bil•i•ty Pronunciation: (hī"pur-ir"i-tu-bil'i-tē), [key] — n. extreme irritability. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Hyperion hyperkalemia Related Content Daily Word Quiz: opulent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language