From The Collaborative International Dictionary of English v.0.48 :
Jakes \Jakes\, n. [Prob. fr. F. Jacques, the proper name. See 2d
Jack.]
A privy. --Shak.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
jakes
n 1: a small outbuilding with a bench having holes through which
a user can defecate [syn: outhouse, privy, earth-
closet, jakes]