The townspeople defiled the river by emptying raw sewage into it.
Examples of defile
defile
They arrested the attacker and charged him with abduction with intent to defile.
From the washingtonpost.com
Today, I watch the Muslim radicals who defile our country as well as their own.
From the news-journalonline.com
Clearly, they simply wanted to defile the church and inflict pain on believers.
From the forbes.com
By their very presence, he believes, the U.S. forces defile the Muslim holy land.
From the time.com
Cook in a manner that preserves and respects nature rather than defile nature.
From the guardian.co.uk
The trail climbs north to a narrow rocky defile forming the entrance to Mica Basin.
From the denverpost.com
Not only does this defile nature, but it leads to a host of health problems.
From the infowars.com
The military derived word defile is occasionally used in the United Kingdom.
From the en.wikipedia.org
If their posters and slogans again defile the city, I'll be glad I've lost my sight.
From the en.wikipedia.org
More examples
A narrow pass (especially one between mountains)
Place under suspicion or cast doubt upon; "sully someone's reputation"
Tarnish: make dirty or spotty, as by exposure to air; also used metaphorically; "The silver was tarnished by the long exposure to the air"; "Her reputation was sullied after the affair with a married man"
Foul: spot, stain, or pollute; "The townspeople defiled the river by emptying raw sewage into it"
(defiled) morally blemished; stained or impure
A way or gorge so narrow that only one person at a time can pass; to make impure; to make dirty
(defiled) impure; dirty
(v.) to make unclean, impure (She defiled the calm of the religious building by playing her banjo.)
To remove abraders from gifts sent to prisons - e.g., The warden was adept at defiling pies.