10
scurvy(noun, adjective, feature, bad, spoil)
10
slimy(adjective, nasty, awful, terrible, horrible)
10
unscrupulous(adjective, mean, nasty, base, dirty)
10
unsporting(adjective, dirty, unreasonable, dishonest, immoral)
9
Fescennine(adjective, feature, bad, awful, decent)
9
begrime(verb, catch, spoil, dirty, stain)
9
blacken(verb, hurt, harm, spoil, dirty)
9
block(verb, catch, hinder, dirty, entangle)
9
clog up(verb, expression, phrasal verb, action, block)
9
crude(adjective, feature, bad, rude, awful)
9
damnable(adjective, bad, evil, nasty, awful)
9
debase(verb, hurt, harm, spoil, dirty)
9
dire(adjective, endured, inexpedience)
9
entangled(adjective, feature, state, bad, awful)
9
flagitious(adjective, feature, bad, awful, negative)
9
grungy(adjective, bad, nasty, dirty, sloppy)
9
horrifying(adjective, feature, bad, awful, endured)
9
immodest(adjective, blue, nasty, offensive, rude)
9
malevolent(adjective, mean, bad, wrong, evil)
9
murky(adjective, obscure, nasty, dark, violent)
10 years ago|60k views|share |citing 
APASmart Define. (2016). foul thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/foul/thesaurus/synonyms
ChicagoSmart Define. 2016. "foul thesaurus" https://smartdefine.org/foul/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, foul thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/foul/thesaurus/synonyms>.
MLASmart Define. "foul thesaurus" 29 March 2016. Web. 24 September 2026. <https://smartdefine.org/foul/thesaurus/synonyms>