The Collaborative International Dictionary of English v.0.48:
co-option \co-option\ n. same as co-optation. [WordNet 1.5]WordNet (r) 3.0 (2006):
co-option n 1: the selection of a new member (usually by a vote of the existing membership) [syn: co-option, co-optation] 2: the act of appointing summarily (with or without the appointee's consent) [syn: co-option, co-optation]