Definition of: correlation

(kôr′ə·lā′shən, kor′-) noun
1. Mutual or reciprocal relation.
2. The act of bringing under relations of union or interaction.
3. Physiol. The combination of nervous impulses in sensory centers resulting in adaptive reactions.
4. Math. A statement of the kind and degree of relationship between two or more variables. Also spelled corelation.
—cor′re·la′tion·al adjective