lion's-ear \ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷\noun (plurallion's-ears) 1.: a mint of the genus Leonotis; especially: a common tropical mint (L. nepetaefolia) 2.: any of various woolly-leaved So. American plants constituting two genera (Culcitium and Espeletia) of the family Compositae 3.: motherwort 1