hairstreak

American

[hair-streek] / ˈhɛərˌstrik /

noun

any small, dark butterfly of the family Lycaenidae, subfamily Theclinae, having hairlike tails on the hindwings.

hairstreak British

/ ˈhɛəˌstriːk /

noun

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

Etymology

Origin of hairstreak

First recorded in 1810–20; hair + streak

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

So far, 11 hairstreak butterflies and three hairstreak caterpillars have been spotted in the area.

From BBC • Apr. 16, 2026

The white-letter hairstreak – whose caterpillars glow under ultraviolet light – has fallen by 80% since the scheme began.

From BBC • Apr. 14, 2026

Orange tip numbers are up more than 40% since 1976, and Black hairstreak - one of the UK's rarest butterflies - is recovering thanks to conservation work.

From BBC • Apr. 14, 2026

The black hairstreak is endangered, the brown hairstreak and white-letter hairstreak are both vulnerable, and green hairstreak and purple hairstreak have also declined in abundance and distribution since the 1970s.

From BBC • Apr. 25, 2025

He's now planting elm hedges to support the elusive white-letter hairstreak butterfly.

From BBC • Mar. 1, 2017

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023