Definitions for tanacetum
Tanacetum, genus Tanacetum(noun)
a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum
U.S. National Library of Medicine
A plant genus of the family ASTERACEAE. Some species of the CHRYSANTHEMUM and the old Pyrethrum genera have been reclassified to this genus. The common name of tansy usually refers to this but also forms part of the common name of other plants such as Tansy Ragwort (SENECIO) and Tansyaster (HAPLOPAPPUS).