noun

• Initialism of National Exhibition Centre, the largest exhibition space in the United Kingdom.
• (politics) Initialism of National Executive Committee, a leadership body of a political party.
• (historical) Initialism of Nippon Electric Company, Ltd. (renamed to NEC in 1983.)
• (US) Initialism of National Electrical Code.
• (astronomy) Initialism of near-Earth comet. [(astronomy) a comet having a period of revolution shorter than 200 years and a perihelion distance smaller than 1.3 au]
• (retail) Initialism of net explosive content.