Answer: befoul

AnswerCrossword Clue
BEFOULSoil
BEFOULSully
BEFOULPollute
BEFOULMake dirty
BEFOULSully.
BEFOULCast aspersions on.
befoulto soil (to make dirty (soiled))
befoulto make dirty or filthy; soil; defile; sully