Main Entry: py·re·thrin

Pronunciation: \pī-ˈrē-thrən, -ˈre-\

Function: noun

Etymology: International Scientific Vocabulary, from Latin pyrethrum

Date: 1871

: either of two oily liquid esters C₂₁H₂₈O₃ and C₂₂H₂₈O₅ having insecticidal properties and occurring especially in the flowers of pyrethrum