WordWeb Online

1. Made dirty or foul
   "breathing air fouled and darkened with factory soot";
   - befouled
    
2. (nautical) not having freedom of motion due to collision or entanglement; entangled
   "with its sails fouled";
   - afoul, foul

1. (baseball) hit a foul ball
    
2. Make impure in a bad way; make something harmful, especially by the addition of some unwanted substance
   "The industrial wastes fouled the lake";
   - pollute, contaminate
    
3. Become or cause to become obstructed
   "The leaves foul our drains in the Fall";
   - clog, choke off, clog up, back up, congest, choke
    
4. Commit a foul; break the rules
    
5. Spoil, spot, stain, or pollute
   "The townspeople fouled the river by emptying raw sewage into it";
   - befoul, defile, maculate [literary]
    
6. Make unclean
   "foul the water"
    
7. Become soiled and dirty

See also: dirty, soiled, tangled, unclean

Type of: attaint [archaic], begrime, bemire [archaic], block, change, close up, colly [archaic], dirty, disgrace, dishonor [US], dishonour [Brit, Cdn], grime, hit, impede, jam, obstruct, obturate, occlude, play, shame, soil

Encyclopedia: Foul