Meaning

noun a canned meat made largely from pork

noun unwanted e-mail (usually of a commercial nature sent out in bulk)

verb send unwanted or junk e-mail

originThe original sense (canned ham) is a proprietary name registered by Geo. A. Hormel & Co. in U.S., 1937. It is presumed to be a conflation of either "spiced ham" or "shoulder of pork and ham" but was soon extended to other kinds of canned meat. Hormel spells the trademarked name in all upper case. The use for unsolicited and unwanted email derives from a Monty Python's Flying Circus sketch. In the…

Etymology from Wiktionary, CC BY-SA 3.0