Definition of "rowan"

Sorbus aucuparia, the European rowan.  examples

Any of various small deciduous trees or shrubs of genus Sorbus, belonging to the rose family, with pinnate leaves, corymbs of white flowers, and usually with orange-red berries.  examples

(obsolete) wych-elm, Ulmus glabra.

Alternative form of rowen (“aftermath”)  examples

(Scotland) dated form of roving (“an elongate bundle of fiber”).  examples

(archaic, Northern England, Scotland, Ireland) Alternative form of rown (“fish-eggs”)