jakes

Pronunciation: \ˈjāks\ (listen to it on m-w.com)

Noun plural (but singular or plural in construction): toilet; outhouse (see definition at dictionary.com)

Etymology: mid 1500s; possibly from the French name Jacques

Usage: It's generally considered a slang term. You could say: I lost my lunch in the jakes. Or She messed herself before she could get to a jakes. Hard to find any Google Book references since doing a search on "jakes" results mostly in books authored by Jakes or with Jakes as a character's name, but here's an interesting one: Google Books: Dictionary of obsolete and provincial English‎ (use the "next" link to see highlighted terms).

Note: Not to be confused with jake which means something else.