Source : WordNet®

pyrethrum
     n 1: made of dried flower heads of pyrethrum plants
     2: white-flowered pyrethrum of Balkan area whose pinnate leaves
        are white and silky-hairy below; source of an insecticide;
        sometimes placed in genus Chrysanthemum [syn: {Dalmatian
        pyrethrum}, {Dalmatia pyrethrum}, {Tanacetum
        cinerariifolium}, {Chrysanthemum cinerariifolium}]
     3: 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 [syn: {painted daisy}, {Tanacetum
        coccineum}, {Chrysanthemum coccineum}]
     4: used in former classifications for plants later placed in
        genus Chrysanthemum and now often included in genus
        Tanacetum [syn: {genus Pyrethrum}]