The Collaborative International Dictionary of English v.0.48:

DJ \DJ\ (d[=e]"j[=a]`) n.
   same as disc jockey. [acronym, capitalized]
   [PJC] Djereed

WordNet (r) 3.0 (2006):

dj
    n 1: a person who announces and plays popular recorded music
         [syn: disk jockey, disc jockey, dj]
    v 1: comment on music to be played; "He has a job disk-jockeying
         on the weekend" [syn: disk-jockey, disc-jockey, DJ]

The Free On-line Dictionary of Computing (30 December 2018):

dj

    The country code for Djibouti.

   (1999-01-27)