Derogitary term, roughly equivalent to idiot. More insulting than berk, but less insulting that gimp.
Thought to originate in the Victorian Era meaning a lower-class foreigner

A cross between a twat, plonker and wanker. Not used as a serious insult, more of a friendly, playful insult.

A Twonk is essentially just a Twink (a scrony prepubescent looking gay man) but lacking the slenderness most commonly associated with twinks, essentially a twonk is just a fat or “husky” twink

You could also think of a twonk as a mix between a twink and a bear

An idiot, a fool

general idiot, someone who has done something stupid, who has cocked up.

Comes from the old school days of the 90s means a cross between a twat and a plonker.

Muppet, idiot, fool, one of little brain power, a tool, a silly sausage, a fuckwit