| Noun | 1. | tansy - common perennial aromatic herb native to Eurasia having buttonlike yellow flower heads and bitter-tasting pinnate leaves sometimes used medicinallycomposite plant, composite - considered the most highly evolved dicotyledonous plants, characterized by florets arranged in dense heads that resemble single flowers genus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum | |