any small, dark butterfly of the family Lycaenidae, having hairlike tails on the hind wings.
Origin of hairstreak
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any small butterfly of the genus Callophrys and related genera, having fringed wings marked with narrow white streaks: family Lycaenidae
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012