Sully

Verb

 * 1)  to soil or stain; to dirty
 * He did not wish to sully his hands with gardening.
 * 1)  to damage or corrupt
 * He did not wish to sully his reputation with an ill-mannered comment.

Thesaurus
abuse, attaint, bedaub, befoul, benasty, besmear, besmirch, besmutch, besoil, bespatter, betray, black, blacken, blemish, blot, blow upon, brand, call names, censure, contaminate, corrupt, daub, debauch, deceive, defame, defile, deflower, demoralize, denigrate, despoil, destroy, dirty, disapprove, discolor, disgrace, disparage, engage in personalities, expose, expose to infamy, force, foul, gibbet, hang in effigy, heap dirt upon, infect, lead astray, mar, mess, mess up, mislead, muckrake, nasty, pillory, pollute, rape, ravage, ravish, reprimand, revile, ruin, seduce, shame, slubber, slur, smear, smirch, smouch, smudge, smut, smutch, soil, spoil, spot, stain, stigmatize, taint, tar, tarnish, throw mud at, vilify, violate, vitiate, wreck