foul -- (an act that violates the rules of a sport)
Overview of verb foul
The verb foul has 7 senses
foul -- (hit a foul ball)
pollute, foul, contaminate -- (make impure; "The industrial wastes polluted the lake")
clog, choke off, clog up, back up, congest, choke, foul -- (become or cause to become obstructed; "The leaves clog our drains in the Fall"; "The water pipe is backed up")
foul -- (commit a foul; break the rules)
foul, befoul, defile, maculate -- (spot, stain, or pollute; "The townspeople defiled the river by emptying raw sewage into it")
cheating, dirty, foul, unsporting, unsportsmanlike -- (violating accepted standards or rules; "a dirty fighter"; "used foul means to gain power"; "a nasty unsporting serve"; "fined for unsportsmanlike behavior")
foul -- ((of a baseball) not hit between the foul lines)
dirty, foul, marked-up -- ((of a manuscript) defaced with changes; "foul (or dirty) copy")
cruddy, filthy, foul, nasty, smutty -- (characterized by obscenity; "had a filthy mouth"; "foul language"; "smutty jokes")
filthy, foul, nasty -- (disgustingly dirty; filled or smeared with offensive matter; "as filthy as a pigsty"; "a foul pond"; "a nasty pigsty of a room")
afoul, foul, fouled -- (especially of a ship's lines etc; "with its sails afoul"; "a foul anchor")