Noun | 1. | genus Oncidium - large genus of showy epiphytic or lithophytic or terrestrial orchids of tropical and subtropical America liliopsid genus, monocot genus - genus of flowering plants having a single cotyledon (embryonic leaf) in the seed family Orchidaceae, orchid family, Orchidaceae - enormous cosmopolitan family of perennial terrestrial or epiphytic plants with fleshy tubers or rootstocks and unusual flowers dancing lady orchid, oncidium, butterfly orchid, butterfly plant - any orchid of the genus Oncidium: characterized by slender branching sprays of small yellow and brown flowers; often grown as houseplants |