Originally Posted by PaulB
As it says, "twit" originally meant a mild rebuke, then the person who given to twitting, and finally it means a silly person. "Twat", as the article says, means the vagina, and is the same as using the "c" word. It's had that meaning for centuries and seems only to have been used interchangeably for "twit" in the last few decades, probably through ignorance.
I clearly didn't express myself well.
Let me put it this way, in all my lie they've both meant you're a f'ing idjit.