'Pyrethrin' definitions:
Definition of 'Pyrethrin'
From: GCIDE
- Pyrethrin \Pyr"eth*rin\, n. [NL. Pyrethrum, generic name of feverfew, Gr. ? feverfew.] (Chem.) A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; -- called also Pyrethrum camphor. [1913 Webster]