For purposes of modern slang, the word was originally developed as a combination of the words COCK and
CUNT for the radio show "Taste of the Goods." CUNK sounded too much like
CUNT for radio. CANK made a better sound for a non gender specific insult involving the genetalia. The final meaning of "cank" is
dumb, and doesn'
t speak (as when arrested), and this stems from old english theives slang. It is also exactly what happens when someone has a cank in their mouth.