| Acronym | Definition |
|---|
| NA | Not Available |
| NA | Not Applicable |
| NA | Natrium (Sodium) |
| NA | North America |
| NA | National Association |
| NA | Nada |
| NA | No Answer |
| NA | National Assembly |
| NA | Native American |
| NA | National Archives |
| NA | Non Turbo (auto) |
| NA | National Academy |
| NA | Namibia (ISO country code, top level domain) |
| NA | Narcotics Anonymous |
| NA | Not Authorized |
| NA | Nurse Assistant |
| NA | National Alliance (white supremacist group) |
| NA | Natural Area (Virginia Parks Department) |
| NA | Netherlands Antilles |
| NA | Nauru (South Pacific country) |
| NA | Neighborhood Association |
| NA | Network Adapter |
| NA | Numerical Aperture |
| NA | Not Approved |
| NA | Needs Assessment |
| NA | numerical analysis |
| NA | Next Action |
| NA | Not Acceptable |
| NA | Nucleic Acid |
| NA | Northern Areas (Pakistan) |
| NA | Non-Alcoholic |
| NA | No Ass |
| NA | No Account |
| NA | Naval Academy |
| NA | National Account |
| NA | No Action |
| NA | Network Analysis |
| NA | No Access |
| NA | Naturally Aspirated |
| NA | Network Administration |
| NA | Noradrenaline |
| NA | No Authority |
| NA | Naughty America |
| NA | Not Assigned |
| NA | National Academies |
| NA | Needle Aspiration (biopsy) |
| NA | Naval Aviator (US Navy) |
| NA | Nerikes Allehanda (Sweden) |
| NA | Not Analyzed |
| NA | Network Appliance |
| NA | No Audio |
| NA | Nuclear Assault (band) |
| NA | Nambia (Africa) |
| NA | Northern Alliance (Afghani resistance to the Taliban) |
| NA | Naval Architect |
| NA | Normally Aspirated |
| NA | Novice Agility (AKC title) |
| NA | Avogadro's Number (chemistry, equal to 6.022e23/Mol; sometimes written as N-Sub-A) |
| NA | No Alarm |
| NA | Not Alarmed |
| NA | Negative Approach (band) |
| NA | Neuroblastoma Cell |
| NA | Natural Adaptation (evolutionary computing) |
| NA | Non-Attainment |
| NA | Naval Aircraft |
| NA | Nigerian Army |
| NA | Normal Adaptation (evolutionary computing) |
| NA | Narcóticos Anónimos |
| NA | Naval Attaché |
| NA | Naruto Arena (game) |
| NA | No Acknowledgment |
| NA | Narcotic Addiction |
| NA | Napoli - Naples (Campania, Italy) |
| NA | Never Available |
| NA | Neutral Axis |
| NA | Negative Affectivity |
| NA | Neuróticos Anónimos (Portugese, Guatemala self help group) |
| NA | National Access |
| NA | Normal Academic |
| NA | Neuraminadase (glycoprotein on influenza virus) |
| NA | Naming Authority |
| NA | Nanoampere |
| NA | Narcotiques Anonymes (Québec) |
| NA | North Allegheny School District (Pittsburgh, Pennsylvania) |
| NA | Ninja Assassins (gaming clan) |
| NA | New Adventures of He-Man (cartoon) |
| NA | National Amusements Inc. |
| NA | Network Aspects |
| NA | Negative Atmosphere |
| NA | Neo America |
| NA | Nurse Associate |
| NA | Nigerian Airways |
| NA | New Assyrian |
| NA | Node Authentication |
| NA | Normal Approval |
| NA | Nitric Anhydride |
| NA | No Acronyms |
| NA | Normal to Abnormal |
| NA | Noctem Aeternus (role playing game) |
| NA | Network Auditor |
| NA | Noob Alert (gaming) |