Definition of locust

• n. - Any one of numerous species of long-winged, migratory, orthopterous insects, of the family Acrididae, allied to the grasshoppers; esp., (Edipoda, / Pachytylus, migratoria, and Acridium perigrinum, of Southern Europe, Asia, and Africa. In the United States the related species with similar habits are usually called grasshoppers. See Grasshopper.
• n. - The locust tree. See Locust Tree (definition, note, and phrases).