to touch or affect (somebody or something) slightly with something bad
to affect (something) with putrefaction; to spoil (something)
to contaminate (somebody) morally; to corrupt (somebody)
archaic said esp of food or water: to become affected with putrefaction; to spoil or go bad
[partly from Middle English tainten to colour, from early French teint, past part. of teindre, from Latin tingere to dip, moisten, tinge; partly fromMiddle English taynten from early French ataint, past part. of ataindre: see attain]