thersitical \thur-SIT-i-kuhl\ (adjective) - Foulmouthed; scurrilous.
"The self-described beneficiaries of most of this I.Q. increase, Princeton's 'Smart Fans,' have railed at season's end against thersitical cheers and jouncing the stands at basketball games."
After Thersites, a Greek in Iliad known for his abusive and foulmouthed nature. He called Agamemnon greedy and Achilles a coward.