What it means: An idiot. Similar to a d*ck in many respects. When to use it: When you see a hen party on a Wednesday afternoon but they're partying like it's a Saturday night. They'll be grinding on an inflatable willy, being rowdy and asking anyone for money all the while attending a garden party hosting afternoon tea. "Look at that bunch of tw*ts." Where it came from: The word may originate from Old Norse 'thevit' which translates as a 'cut' or 'slit.'