WordNet sense 1 (highly offensive; arousing aversion or disgust):

disgusting, distasteful, loathsome, repellent, revolting, wicked, yucky, disgustful, loathly, repellant, repelling, skanky, wicked

WordNet sense 2 (unpleasant or disgusting especially to the senses):

offensive

WordNet sense 3 (become or cause to become obstructed):

choke, clog, congest, back up, choke off, clog up

WordNet sense 4 ((of a manuscript) defaced with changes):

marked-up

WordNet sense 5 (offensively malodorous):

fetid, funky, noisome, smelly, stinking, foetid, foul-smelling, ill-scented

WordNet sense 6 (having an unpleasant smell):

malodorous, stinky, malodourous, unpeasant-smelling

WordNet sense 7 (violating accepted standards or rules):

unsportsmanlike, cheating, unsporting

WordNet sense 8 (not fair; marked by injustice or partiality or deception):

unfair, unjust

WordNet sense 9 (make impure):

contaminate, pollute

WordNet sense 10 (spot, stain, or pollute):

befoul, defile, maculate, defile

WordNet sense 11 (characterized by obscenity):

filthy, nasty, smutty

WordNet sense 12 ((of behavior or especially language) characterized by obscenity or indecency):

dirty

WordNet sense 13 (soiled or likely to soil with dirt or grime):

unclean, soiled

WordNet sense 14 (especially of a ship's lines etc):

afoul, fouled

WordNet sense 15 (in a confused mass):

tangled