taint

from The American Heritage® Dictionary of the English Language, 5th Edition.

• transitive verb To affect or associate with something undesirable or reprehensible.
• transitive verb To expose to an infectious agent, toxin, or undesirable substance.
• transitive verb To subject to decay or putrefaction: synonym: contaminate.
• noun An undesirable or corrupting influence or association: synonym: stain.
• noun An undesirable quality; a defect or shortcoming.
• noun The perineum.

from The Century Dictionary.

• To tinge; tincture; hence, to imbue; touch; affect.
• To imbue with something of a deleterious or offensive nature; infect or impregnate with a noxious substance or principle; affect with insalubrity, contagion, disease, or the like.
• To make noisome or poisonous in constitution; corrupt the elements of; render putrid, deleterious, or unfit for use as food or drink.
• To corrupt morally; imbue with perverse or objectionable ideas; exert a vitiating influence over; pervert; contaminate.
• To give a corrupted character or appearance to; affect injuriously; stain; sully; tarnish.
• To disgrace; fix contumely upon.
• To treat with a tincture; embrocate; mollify.
• = Syn. 2-5. Contaminate, Defile, Taint, Pollute, Corrupt, Vitiate. Whether these words are regarded as meaning the injuring of purity or the spoiling of value, they are in the order of strength, except that each is used in different degrees of strength, and that vitiate is one of the weaker words and taint a strong word for rendering impure. Corrupt means the absolute destruction of purity. They all suggest an influence from without coming upon or into that whose purity or value is injured.
• To be tinged or tinctured; become imbued or touched.
• To become tainted or rancid; be affected with incipient putrefaction.
• Tainted; touched; imbued.
• To attaint.
• To touch or hit in tilting; reach with a thrust, as of a lance or other weapon.
• To thrust, as a lance or other weapon, especially in tilting.
• To make an effort or essay, as a juster; tilt, as in the just; make a thrust.
• noun A thrust, as of a lance in tilting; especially, a preliminary movement or trial with a weapon, as in the tilt, or, by extension, in battle.
• noun Color; hue; dye; tinge.
• noun A stain; a spot; a blemish; a touch of discredit or dishonor.
• noun An infecting tinge; a trace; a touch.
• noun A corrupting or contaminating influence, physical or moral; a cause or condition of depravation or decay; an infection.
• noun A certain spider of small size and red color, reputed to be poisonous: perhaps a species of Latrodectus, but probably only a harvest-mite, and not poisonous.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb obsolete To thrust ineffectually with a lance.
• transitive verb To imbue or impregnate with something extraneous, especially with something odious, noxious, or poisonous; hence, to corrupt; to infect; to poison.
• transitive verb Fig.: To stain; to sully; to tarnish.
• noun obsolete A thrust with a lance, which fails of its intended effect.
• noun obsolete An injury done to a lance in an encounter, without its being broken; also, a breaking of a lance in an encounter in a dishonorable or unscientific manner.
• intransitive verb To be infected or corrupted; to be touched with something corrupting.
• intransitive verb To be affected with incipient putrefaction.
• transitive verb Aphetic form of attaint.
• transitive verb obsolete To injure, as a lance, without breaking it; also, to break, as a lance, but usually in an unknightly or unscientific manner.
• transitive verb obsolete To hit or touch lightly, in tilting.
• noun obsolete Tincture; hue; color; tinge.
• noun Infection; corruption; deprivation.
• noun A blemish on reputation; stain; spot; disgrace.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun slang The perineum.
• noun A contamination, decay or putrefaction, especially in food
• noun A mark of disgrace, especially on one's character; blemish
• noun obsolete tincture; hue; colour
• noun obsolete infection; corruption; deprivation
• verb To contaminate or corrupt (something) with an external agent, either physically or morally.
• verb To spoil (food) by contamination.
• noun A thrust with a lance, which fails of its intended effect.
• noun An injury done to a lance in an encounter, without its being broken; also, a breaking of a lance in an encounter in a dishonorable or unscientific manner.