The acronym DNC can mean:

Democratic National Convention

Dilation and curettage, a medical procedure to "clean out" the uterus

Director of Naval Construction, a senior post in the British Admiralty

Digital Nautical Chart, the electronic data necessary to present a nautical chart on a PC running an ECDIS (Electronic Chart Display and Information System) or ECS (Electronic Chart System) software program for marine navigation

United States National Do Not Call Registry

Direct Numerical Control, in manufacturing, means to network your CNC equipment to your PCs.

"Does not compute"

Canadian Do Not Call List

Democratic National Committee, the principal campaign and fund-raising organization affiliated with the United States Democratic Party

Declared net capacity, a measure of the contribution that a power station makes to the distribution grid (developed net capacity in British English)

Daigaku Nyūshi Center, a Japanese Independent Administrative Institution which administers National Center Test for University Admissions