Source : Webster's Revised Unabridged Dictionary (1913)

Spay \Spay\, v. t. [imp. & p. p. {Spayed}; p. pr. & vb. n.
   {Spaying}.] [Cf. Armor. spac'hein, spaza to geld, W. dyspaddu
   to geld, L. spado a eunuch, Gr. ?.]
   To remove or extirpate the ovaries of, as a sow or a bitch;
   to castrate (a female animal).

Spay \Spay\, n. [Cf. {Spade} a spay, {Spay}, v. t.] (Zo["o]l.)
   The male of the red deer in his third year; a spade.

Source : WordNet®

spay
     v : remove the ovaries of; "Is your cat spayed?" [syn: {alter},
         {neuter}, {castrate}]