Is it "kitty-corner"? "Catty-corner"? I've always wanted to know. Now that I finally have an audience (you) to witness my discovery, I can find out.
So I finally look it up and I see that, most properly, it's neither.
(noticed the "d" at the end)
adj., adv. cater-cornered: also, kitty-corner
That's from "Webster's New World College." "American Heritage" says the same thing: that the proper term has a d at the end (I don't like that one little bit. Who's going to say, "The post office is kitty-cornered from the drugstore"?)
So, for schticks and giggles, I checked my 1933 "Oxford Universal Dictionary." According to this one, there is no "kitty-corner." There is no "kitty-cornered." There is no "cater-cornered" (apparently back in those days nothing was ever located diagonal to anything else). So I looked up "cater," which had some obvious definitions plus another that was a new one on me:
"To set rhomboidally; to cut, go, etc. diagonally."
Perhaps it wasn't until 1934 that someone first observed a cat blatantly disregarding a marked crosswalk.