To Befoul

1. To make foul; to soil; to contaminate, pollute.
2. (specifically) To defecate on, to soil with excrement.
3. (figurative) To stain or mar (for example with infamy or disgrace).
4. To entangle or run against so as to impede motion. (The addition of quotations indicative of this usage is being sought):

Synonyms

• (stain or mar): besmirch, sully, tarnish