Word Study
pyrethrin
CIDE DICTIONARY
pyrethrin, n. [NL. Pyrethrum, generic name of feverfew, Gr. feverfew.].
A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; -- called also Pyrethrum camphor . [1913 Webster]
OXFORD DICTIONARY
pyrethrin, n. any of several active constituents of pyrethrum flowers used in the manufacture of insecticides.
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