/ˈpɪəθrəm/ PY-ur-thrum

Definitions

1. noun

a plant of the genus Chrysanthemum, especially C. cinerariaefolium, from which pyrethrum insecticides are extracted.

“The gardener used pyrethrum to control the aphid infestation in the garden.”

2. noun

a type of insecticide derived from the pyrethrum plant.

“The farmer applied pyrethrum to the crops to prevent damage from pests.”