/ Dictionary / Index H hydrocyanic: Meaning and Definition of Find definitions for: hy•dro•cy•an•ic Pronunciation: (hī"drō-sī-an'ik), [key] — adj. of or derived from hydrocyanic acid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hydrocracking hydrocyanic acid Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language