- a small tree or shrub belonging to the genus Acacia, of the mimosa family, having clusters of small yellow flowers.
- any of several other plants, as the locust tree.
- gum arabic.
- any shrub or tree of the tropical and subtropical leguminous genus Acacia, having compound or reduced leaves and small yellow or white flowers in dense inflorescencesSee also wattle 1 (def. 4)
- false acacia another name for locust (def. 2), locust (def. 3)
- gum acacia another name for gum arabic
1540s, from Latin acacia, from Greek akakia “thorny Egyptian tree,” perhaps related to Greek ake “point, thorn,” from PIE root *ak- “sharp” (see acrid). Or perhaps a Hellenization of some Egyptian word. From late 14c. in English as the name of a type of gum used as an astringent, etc.