1. befoul The hand may be defiled by a touch of pitch; swine that have been wallowing in the mud are befouled. Contaminate and infect refer to something evil that deeply pervades and permeates, as the Synonyms: defile, befoul, corrupt, pollute, spoil, sully, tarnish, contaminate, infect, soil, stain, taint, vitiate Antonyms: clean, cleanse, disinfect, hallow, purify, sanctify, wash