pyrethrum vs insecticide

pyrethrum and insecticide both are nouns.

Word	Noun	Adjective	Verb	Adverb
pyrethrum	Yes	No	No	No
insecticide	Yes	No	No	No

As nouns, insecticide is a hypernym of pyrethrum; that is, insecticide is a word with a broader meaning than pyrethrum:

Other hypernyms of pyrethrum include insect powder.

pyrethrum (noun)	insecticide (noun)
spring-flowering garden perennial of Asiatic origin having finely divided aromatic leaves and white to pink-purple flowers; source of an insecticide; sometimes placed in genus Chrysanthemum	a chemical used to kill insects
white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum
made of dried flower heads of pyrethrum plants