genus Iris ge·nu·si·ris uncommon noun 1. large genus of perennials that develop from bulbs or rhizomes Synonymsgenus Iris Related words Broader terms liliid monocot genusIridaceae Narrower terms bulbous iris Part of irisbearded irisbeardless iris WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.