The Collaborative International Dictionary of English v.0.48:
Pie \Pie\, n. [F. pie, L. pica; cf. picus woodpecker, pingere to
paint; the bird being perhaps named from its colors. Cf.
Pi, Paint, Speight.]
(a) A magpie.
(b) Any other species of the genus Pica, and of several
allied genera. [Written also pye.]
2. (R. C. Ch.) The service book.
3. (Pritn.) Type confusedly mixed. See Pi.
By cock and pie, an adjuration equivalent to "by God and
the service book." --Shak.
Tree pie (Zool.), any Asiatic bird of the genus
Dendrocitta, allied to the magpie.
Wood pie. (Zool.) See French pie, under French.