WTF

WTF abbr. for "Where's The Fish", used by failed Norwegian politician Stig Cod in his doomed 1998 election campaign

Extra

Extra N. A short form of HEXTRAY, a six-holed plastic tray for drinks cups, due to baffle future archaeologists

Spam

Spam n. An offer you didn't request for a product you don't need that you can't help mentioning e.g. "I had 573 spams this week"

Hashtag

Hashtag n. A device for labelling and identifying mixes of corned beef and other substances, in an effort to create something edible