Green’s Dictionary of Slang

1. to hit someone.

1984		A. Sayle Train to Hell 126: Then she twatted me on the head with the cash register.
1998		Indep. on Sun. Culture 11 Oct. 9: With their perpetual drunkenness, big arms, and talk of twatting poofs.
2007		A. Guthrie Hard Man 214: I twatted him a beauty.
2019		Twitter 27 Jan. 🌐 2016: ‘The NHS will be up to its fucking tits in money.’ 2019: ‘You’ll be twatted in the back of your stupid fucking head with the butt of a military grade assault rifle if you dare to leave your soon-to-be-repossessed house’.

2. to behave in an unsophisticated manner.

1999

Guardian Guide 15–21 May 25: The two dizzy sorts [...] twatting about in service station sunglasses.

3. to waste time.

2000

Hip-Hop Connection Jan.–Feb. 35: So don’t twat about.