(1):

(v. i.) To act as, or convey, a poison.

(2):

(n.) Any agent which, when introduced into the animal organism, is capable of producing a morbid, noxious, or deadly effect upon it; as, morphine is a deadly poison; the poison of pestilential diseases.

(3):

(n.) To injure or kill by poison; to administer poison to.

(4):

(n.) To taint; to corrupt; to vitiate; as, vice poisons happiness; slander poisoned his mind.

(5):

(n.) To put poison upon or into; to infect with poison; as, to poison an arrow; to poison food or drink.

(6):

(n.) That which taints or destroys moral purity or health; as, the poison of evil example; the poison of sin.