What does ENK stand for?

Endo-atmospheric Non-nuclear Kill (SAUS)

Enerteck Energy Technologies Corp. - Vancouver Stock Exchange symbol

Enkephalin - Brain peptide, subclass of Endorphin

Enniskillen - Northern Ireland - Airport symbol (AD)

Enter Key - Computer science (IAA)

Expected Number of Kills - Military (MCD)

Liquavator Manufacturing, Magnolia, TX - Manufacturer code for watercraft hull identification number (USCG)

England - MARC country of publication code - Library of Congress (LCCP)