The Collaborative International Dictionary of English v.0.48:
Bail \Bail\, n. [OF. bail, baille. See Bailey.]
1. (Usually pl.) A line of palisades serving as an exterior
defense. [Written also bayle.] [Obs.]
2. The outer wall of a feudal castle. Hence: The space
inclosed by it; the outer court. --Holinshed.
3. A certain limit within a forest. [Eng.]
4. A division for the stalls of an open stable.
5. (Cricket) The top or cross piece (or either of the two
cross pieces) of the wicket.