Definition of "poison"

A substance that is harmful or lethal to a living organism when ingested.  examples

(figuratively) Anything harmful to a person or thing.  quotations  examples

(informal) An intoxicating drink; a liquor. (note: this sense is chiefly encountered in the phrases "name your poison" and "what's your poison ?")  examples

(chemistry) Any substance that inhibits catalytic activity.  quotations  examples

(transitive) To use poison to kill or paralyse (somebody).  examples

(transitive) To pollute; to cause to become poisonous.  examples

(transitive) To cause to become much worse.  examples

(transitive) To cause (someone) to hate or to have unfair negative opinions.  examples

(chemistry) To inhibit the catalytic activity of.  examples

(transitive, computing) To place false information into (a cache) as part of an exploit.  quotations  examples