D defs.my
Entry 1 sense Webster, 1913

Pyrethrin

· Pyr·eth·rin · IPA
01 n. A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; -- called also Pyrethrum camphor.
  1. 1.
    A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; -- called also Pyrethrum camphor.(Chem.) Also: Pyrethrum camphor