The Collaborative International Dictionary of English v.0.48:
Citroncirus \Citroncirus\ n. a cross between Citrus sinensis and Poncirus trifoliata. Syn: genus Citroncirus. [WordNet 1.5]WordNet (r) 3.0 (2006):
Citroncirus n 1: a cross between Citrus sinensis and Poncirus trifoliata [syn: Citroncirus, genus Citroncirus]