DCD is a three-letter abbreviation with multiple meanings, including:
Data Carrier Detect, a term used with modems. Also see RS-232.
Direct conversion device, a device that directly converts energy from one form to another
Dead Can Dance is an originally Australian eclectic band, popular among goth music listeners.
Def Con Dos is a Spanish rap metal band.
Diamond Comic Distributors is the largest distributor (not publisher) of comic books in the United States
never heard of it before