befoul

1 to make dirty unsightly mud and slush befouls the family car every winter Synonyms dirty, begrime, bemire, besmirch, blacken, daub, distain [archaic], foul, gaum [dialect], grime, mire, muck, muddy, smirch, smudge, soil, stain, sullyRelated Words contaminate, defile, pollute, taint; discolor; confuse, disarrange, disarray, dishevel, disorder, draggle, jumble, mess, muddle; colly [chiefly British dialect], crock [dialect]Near Antonyms decontaminate, purge, purify; disinfect, sanitize; brush, dry-clean, dust, launder, mop, rinse, scour, scrub, sweep, wash, wipe; brighten, deodorize, freshen, renew, spruce (up); straighten (up), tidy (up)Antonyms clean, cleanse

2 to make unfit for use by the addition of something harmful or undesirable the enemy had befouled the water in all of the area's wells with animal carcasses Synonyms contaminate, defile, foul, poison, pollute, taintRelated Words infect; begrime, besmirch, blacken, dirty, foul up, grime, mire, muddy, smirch, smudge, soil, stain, sully; corrupt, rot, spoil; adulterate, doctor; dilute, water downNear Antonyms clarify, clean, cleanse, clear, distill (also distil), purge; filter; disinfect, sanitize, sterilizeAntonyms decontaminate, purify