pyrethrin

(redirected from pyrethrin I)
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pyrethrin

/py·reth·rin/ (pi-reth´rin) either of two esters, p. I and p. II, found in the flowers of certain species of Chrysanthemum; used as an insecticide and as a topical pediculicide.

pyrethrin

Public health A topical insecticide used to manage head lice. See Head lice.