Source : Webster's Revised Unabridged Dictionary (1913)

Colleague \Col"league\ (k[o^]l"l[=e]g), n. [F. coll[`e]gue, L.
   collega one chosen at the same time with another, a partner
   in office; col- + legare to send or choose as deputy. See
   {Legate}.]
   A partner or associate in some civil or ecclesiastical office
   or employment. It is never used of partners in trade or
   manufactures.

   Syn: Helper; assistant; coadjutor; ally; associate;
        companion; confederate.

Colleague \Col*league"\ (k[o^]l*l[=e]g"), v.t & i.
   To unite or associate with another or with others. [R.]
   --Shak.

Source : WordNet®

colleague
     n 1: an associate you work with [syn: {co-worker}, {fellow worker},
           {workfellow}]
     2: a person who is member of your class or profession; "the
        surgeon consulted his colleagues"; "he sent e-mail to his
        fellow hackers" [syn: {confrere}, {fellow}]