The Collaborative International Dictionary of English v.0.48:
Meninges \Me*nin"ges\ (m[-e]*n[i^]n"j[=e]z), n. pl.; sing. Meninx (m[-e]*n[i^][ng]ks"). [NL., fr. Gr. mh^nigx, mh^niggos, a membrane.] (Anat.) The three membranes that envelop the brain and spinal cord; the pia mater, dura mater, and arachnoid membrane. [1913 Webster]WordNet (r) 3.0 (2006):
meninx n 1: a membrane (one of 3) that envelops the brain and spinal cord [syn: meninx, meninges]