Na 1The symbol for sodium.[From New Latin natrium, from French natron, natron; see natron.]Na 2abbr. Bible NahumnAabbr. nanoampereNAabbr.1. Narcotics Anonymous2. North America3. also n/a not applicableAmerican Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.n/a abbreviation for not applicable Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014NA 1. not applicable. 2. not available. Na Chem. Symbol. sodium. [