The Collaborative International Dictionary of English v.0.48:

Ethylate \Eth"yl*ate\ ([e^]th"[i^]l*[asl]t), n. [From Ethyl.]
   (Chem.)
   A compound derived from ethyl alcohol by the replacement of
   the hydroxyl hydrogen, after the manner of a hydrate; an
   ethyl alcoholate; as, potassium ethylate, C2H5.O.K.
   [1913 Webster]