Source : Webster's Revised Unabridged Dictionary (1913)

Correlate \Cor`re*late"\ (k[o^]r`r[-e]*l[=a]t" or
   k[o^]r"r[-e]*l[=a]t`), v. i. [imp. & p. p. {Correlated}; p.
   pr. & vb. n. {Correlating}.] [Pref. cor- + relate.]
   To have reciprocal or mutual relations; to be mutually
   related.

         Doctrine and worship correlate as theory and practice.
                                                  --Tylor.

Correlate \Cor`re*late"\, v. t.
   To put in relation with each other; to connect together by
   the disclosure of a mutual relation; as, to correlate natural
   phenomena. --Darwin.

Correlate \Cor"re*late\ (k?r"r?-l?t), n.
   One who, or that which, stands in a reciprocal relation to
   something else, as father to son; a correlative. --South.

Source : WordNet®

correlate
     adj : mutually related [syn: {correlative}, {correlated}]

correlate
     n : either of two correlated variables [syn: {correlative}]
     v 1: to bear a reciprocal or mutual relation; "Do these facts
          correlate?"
     2: bring into a mutual, complementary, or reciprocal relation;
        "I cannot correlate these two pieces of information"