cluster bean clus·ter·bean uncommon noun 1. drought-tolerant herb grown for forage and for its seed which yield a gum used as a thickening agent or sizing material Synonymsguarcluster beanCyamopsis tetragonolobusCyamopsis psoraloides Related words Broader terms legume Parts Cyamopsis WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
