pyrethrum

py·re·thrum

noun \pī-ˈrē-thrəm, -ˈreth-rəm\

Definition of PYRETHRUM

1

: any of several chrysanthemums with finely divided often aromatic leaves including ornamentals as well as important sources of insecticides

2

: an insecticide consisting of or derived from the dried heads of any of several Old World chrysanthemums (genus Chrysanthemum of the family Compositae)