noun: (pharmacology) A taxane antineoplastic drug C₄₇H₅₁NO₁₄ originally isolated from the bark of the Pacific yew, Taxus brevifolia, but now typically derived as a semisynthetic product of the English yew; it interferes with microtubule function and inhibits cell division, and is used in the treatment of some cancers, especially those of the breast and ovary.
