To hit/kick something (usually a ball) hard, especially in sport, e.g. football, pool. Not really for use in fight situations, e.g. you cant say "Twont that dude in the face"
Related to the word twat, e.g. to twat a ball

someone who is sexy beyond mean

a contraction of "it will not" with a ye olde flavour to it

Other definitions are wrong or derivative of the original. True definition
(English) Slang for Perineum (only) of female (area of skin between anus and vagina). The origin is a northern or old English contraction for "if it wasn't" and based on a joke as per example

Someone who refuses to use Twitter, on account of it being for twats.