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):
Poncirus trifoliata n 1: small fast-growing spiny deciduous Chinese orange tree bearing sweetly scented flowers and decorative but inedible fruit: used as a stock in grafting and for hedges [syn: trifoliate orange, trifoliata, wild orange, Poncirus trifoliata]