What does the acronym DJ stand for?

It stands for Disk Jockey. In the "olden days," radio stations played music from vinyl records on turn tables. These were alternatively called disks. So, the disk jockey was the one who "jockeyed" the disks onto the turntable and introduced the songs. The term remained as playing music shifted to tapes, CDs and, now, I suspect onto computers.

Others:

DJ

Dow Jones

DJ Disc Jockey DJ Dow Jones DJ Dae Jung Kim (Korean president) DJ Dale Jarrett (Nascar driver) DJ Dark Jedi (gaming clan) DJ Davey Jones (locker) DJ David Jones (Australian store) DJ Dead Journal DJ Dear John (break up letter) DJ Deceptive Jamming DJ Dennis Johnson (basketball player; football player) DJ Derek Jeter (baseball player) DJ Desk Jockey (bureaucrat) DJ DeskJet (Hewlett Packard) DJ Deterministic Jitter DJ Digital Jockey DJ Digital Journalist DJ Digital Jukebox (Dell) DJ Dinner Jacket DJ Director of Journals DJ Dirt Jumping (cycling) DJ Distributed Jamming DJ Distributed JANUS DJ District Judge DJ Djibouti DJ

Don Juan DJ

Donna Jo (TV sitcom Full House) DJ Drill Jig DJ Dust Jacket (book condition) DJ Dust Jacket (hardbound books)

DJ Kim Dae Jung (a Korean president) If referring to someone who plays songs, and not someone's initials, then DJ stands for "Disc Jockey".