locust

Concise Oxford English Dictionary © 2008 Oxford University Press:
locust/ˈləʊkəst/

▶noun

• 1 a large, mainly tropical grasshopper which migrates in vast swarms and is very destructive to vegetation. [Locusta migratoria and other species.]

• 2 (also locust tree) a carob tree, false acacia, or similar pod-bearing tree.

– origin ME: via OFr. locuste from L. locusta ‘locust, crustacean’.