Answer: befouls

AnswerCrossword Clue
BEFOULSPollutes
BEFOULSStains
BEFOULSDefiles or pollutes
BEFOULSStains or defiles
befoulsBEFOUL, to soil (to make dirty (soiled))
befoulsto make dirty or filthy; soil; defile; sully