Wild-Assed-Guess
You need to get out more.
1920's and 1930's slang I know pretty well. But I never heard of that one, or many other currently used computer-generation "initial abbreviation" terms.
Getting out more? Okay how about a trip to Fort Washington & The Stoogeum in late April...
Actually, I'm also off to Cinefest in Syracuse next week.
Info here:
http://www.syracusecinephile.com/Anyone else going?
Lots of rare films shown, including one Three Stooges-related: the 1941 Universal comedy TIGHT SHOES with Shemp Howard.
Regarding "WAG" - if you had given me 1,000 guesses I would never have been able to figure out what you meant by that.
Is there anyone else out there who knew what it meant?