(idiomatic, vulgar, followed by a wh-clause) I don't know; nobody knows; it is unclear.

(Australia, vulgar, slang) Vicious, aggressive, intimidating. / (Australia, Britain, vulgar, slang) Dissuasively or intimidatingly large; massive.

(Australia, vulgar, slang) Excessively

(vulgar, slang, derogatory, Australia, New Zealand, UK) Term of abuse.

Alternative spelling of fuck-knuckle

(vulgar, slang) To actively sexually penetrate someone's mouth; to have vigorous oral sex. / (vulgar, slang) To sexually penetrate someone's eye socket.

(idiomatic, colloquial, vulgar) An expression of anger or frustration.

(vulgar, slang) A person's facial expression during orgasm.

(transitive, vulgar) to cheat or treat unfairly (to exploit somebody in a way which results in an advantage to oneself, at the cost of the other party gaining a considerable disadvantage)

(idiomatic, vulgar, chiefly in the negative) To care; to give a shit.