defile

(noun) a narrow pass (especially one between mountains). Synonyms: gorge.

(verb) place under suspicion or cast doubt upon. Synonyms: sully, corrupt, taint, cloud. Example: "Sully someone's reputation."

(verb) make dirty or spotty, as by exposure to air; also used metaphorically. Synonyms: tarnish, stain, maculate, sully. Examples: "The silver was tarnished by the long exposure to the air." "Her reputation was sullied after the affair with a married man."

(verb) spot, stain, or pollute. Synonyms: foul, befoul, maculate. Example: "The townspeople defiled the river by emptying raw sewage into it."