The NEC is the National Exhibition Centre, a huge modern site just outside Birmingham in the middle of England. People go there for big shows and conferences. The motor show is the famous example, but the same halls hold trade fairs, exhibitions, and other large events. In British English, 'the NEC' works like a place name: you are going to the NEC, you have a stand at the NEC. It is an abbreviation, not a word you change into necs or necing. Though actually, those three letters are busy in the world. A Japanese electronics company is also called NEC, and that is a completely different thing. This entry is only the exhibition centre near Birmingham.