bugbaneDefinition of bugbane noun a tall plant of the buttercup family, with spikes of cream or yellow flowers and fern-like leaves, native to north temperate regions. Genus Cimicifuga, family Ranunculaceae: several species, in particular C. foetida Origin: early 19th century: from bug + bane, with reference to the former use of the species C. foetida to drive away bedbugsbugbane in other Oxford dictionaries Definition of bugbane in the US English dictionary