The Oxford Dictionary of Canadian English.
Slang is a touchy issue in Canada. When The Oxford Dictionary of Modern Slang appeared in 1992, none of the derivations was attributed to Canada. A newspaper columnist suggested the word "scuzz" might be Canadian, because Oxford had quoted a usage from Margaret Atwood. But that was pretty much it. The Oxford Dictionary will redress this grievance. Words like "bargoon" for bargain, and "bird course" for what we call "gut" courses in college, have been duly noted. "Have had the biscuit" means "to be done for," and is not to be confused with the British expression "to take the biscuit," which means "to take the cake." A "forty pounder" is a 40-ounce bottle of liquor, much in evidence on sultry Saturday nights in Saskatoon. Barber has become an expert on underwear argot: "gaunch," "gotch," "gitch," "ginch," etc.
I give in. Any language with four words for underwear certainly deserves its own dictionary.
Alex Beam is a columnist at the Boston Globe. His e-mail address is firstname.lastname@example.org.