scurrilous [skur-uh-luhs, skuhr- ]
1 Making or spreading scandalous claims about someone with the intention of damaging their reputation.
2 Humorously insulting
Every two years the American politics industry fills the airwaves with the most virulent, scurrilous, wall-to-wall character assassination of nearly every political practitioner in the country — and then declares itself puzzled that America has lost trust in its politicians. (Charles Krauthammer, Policitcal Suicide, The Washington Post, 1994)
Curse you and your vile hints, you mongrel, you hanger-on, you scurrilous beast. (E Phillips Oppenheim, A Millionaire of Yesterday )
In Ambrakia once Pyrrhus was advised to banish a man who abused him in scurrilous terms. (Aubrey Stewart & George Long, Plutarch's Lives)
'using such language as only the licence of a buffoon can warrant' [Johnson], 1570s, from scurrile 'coarsely joking' (c. 1500, implied in scurrility), from Latin scurrilis 'buffoonlike,' from scurra 'fashionable city idler, man-about-town,' later 'buffoon.' According to Klein's sources, 'an Etruscan loan-word.' (Online Etymology Dictionary)