pyrethrin

Either of two viscous liquid esters, C₂₁H₂₈O₃ or C₂₂H₂₈O₅, that are extracted from pyrethrum flowers and used as insecticides.

A resinous compound found in pellitory resin from the root of Anacyclus Pyrethrum.

A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; — called also Pyrethrum camphor.

Any of a number of naturally occurring insecticides extracted from the pyrethrum plant; unusual in having a cyclopropane ring.