WordNet sense 1 (corrupt morally or by intemperance or sensuality):

debase, debauch, demoralize, deprave, misdirect, pervert, profane, subvert, vitiate, demoralise, pervert

WordNet sense 2 (not straight; dishonest or immoral or evasive):

crooked, crooked

WordNet sense 3 (make illegal payments to in exchange for favors or influence):

bribe, buy, grease one's palms

WordNet sense 4 (not perfect; defective or inadequate):

imperfect

WordNet sense 5 (place under suspicion or cast doubt upon):

cloud, defile, sully, taint, defile

WordNet sense 6 (touched by rot or decay):

tainted

WordNet sense 7 (having or disintegrated; usually implies foulness):

rotten

WordNet sense 8 (morally corrupt or evil):

putrid

WordNet sense 9 (marked by immorality; deviating from what is considered right or proper or good):

depraved, immoral, perverse, perverted, reprobate

WordNet sense 10 (ruined in character or quality):

corrupted, debased, vitiated

WordNet sense 11 (alter from the original):

spoil