/ Dictionary / Index H hairstreak: Meaning and Definition of Find definitions for: hair•streak Pronunciation: (hâr'strēk"), [key] — n. any small, dark butterfly of the family Lycaenidae, having hairlike tails on the hind wings. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hairstreak (Thesaurus) hairspring hair stroke 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