noun

1. any of various large grasshoppers; specif., a migratory grasshopper often traveling in great swarms and destroying nearly all vegetation in areas visited
2. seventeen-year locust
3. 1. a spiny tree (Robinia pseudoacacia) of the pea family, native to the E or Central U.S. and having long pendulous racemes of fragrant white flowers
      also called black locust or yellow locust
   2. the yellowish, hard, durable wood of this tree
4. any honeylocust
5. carob (sense )

Etymology: ME < L locusta, prob. akin to lacerta, lizard