plural of NEC

Not Elsewhere Classified, a phrase used in classification codes such as Standard Industrial Classification, International Standard Classification of Occupations, DSM-IV-TR, DSM-5, ICD-9, and ICD-10.

National Exhibition Centre. The largest exhibition space in the United Kingdom. / National Executive Committee (of a political party).

(astronomy) Initialism of near-Earth comet.

(medicine, colloquial) Necrotizing fasciitis.