Real Dictionary

correlate
verb: If one thing correlates with another, there is a close similarity or connection between them, often because one thing causes the other. You can also say that two things correlate.
verb: If you correlate things, you work out the way in which they are connected or the way they influence each other.

correlate in American English
closely and naturally related
either of two interrelated things, esp. if one implies the other
to be mutually related (to or with)
to bring (a thing) into mutual relation (with another thing); calculate or show the reciprocal relation between; specif., to bring (one of two related or interdependent quantities, sets of statistics, etc.) into contrast (with the other)
adjective: mutually or reciprocally related
intransitive verb: to have a mutual or reciprocal relation; stand in correlation
noun: either of two related things, esp. when one implies the other
transitive verb: to place in or bring into mutual or reciprocal relation; establish in orderly connection

correlate in British English
adjective: having a mutual, complementary, or reciprocal relationship
noun: either of two things mutually or reciprocally related
verb: to place or be placed in a mutual, complementary, or reciprocal relationship