Definition of: poison

(poi′zən) noun
1. Any substance which, introduced into an organism in relatively small amounts, acts chemically upon the tissues to produce serious injury or death.
2. Physics Any substance or material which, by absorbing neutrons, prevents fission in an atomic reactor.
3. Anything that tends to taint or destroy character or to mislead, corrupt, or pervert.
—v.t.
1. To administer poison to; kill or injure with poison.
2. To put poison into or on.
3. To affect wrongfully; corrupt; pervert: to poison one's mind.
—adjective Killing; venomous; corrupting. [<OF <L potio, -onis a drink, poisonous draft. Doublet of POTION.]
—poi′son·er noun