| Acronym | Definition |
|---|
| NSI➣No Smoking Indoors |
| NSI➣Network Solutions, Inc. |
| NSI➣National Security Information |
| NSI➣Nutraceutical Sciences Institute (vitamin producer) |
| NSI➣National Standards Institute |
| NSI➣Natural Science Industries (Farmingdale, NY) |
| NSI➣North-South Institute (Canadian Economic Think Tank) |
| NSI➣Nuovi Stati Indipendenti (Italian: New Independent States) |
| NSI➣Name Service Interface |
| NSI➣Network Store Interface |
| NSI➣Norton System Information |
| NSI➣Non Sna Interconnection |
| NSI➣Network Solutions Inc. |
| NSI➣Network Store Information |
| NSI➣Network System Interface |
| NSI➣Network Side Interface |
| NSI➣North Star Imaging (Rogers, MN) |
| NSI➣National System of Innovation (various nations) |
| NSI➣NASA Science Internet |
| NSI➣Naviguer Sur Internet (French: Surfing the Internet) |
| NSI➣National Systems Integrator (Microsoft) |
| NSI➣Nova Slovenija (New Slovenia) |
| NSI➣Needlestick and Sharps Injuries |
| NSI➣National Security Intelligence (fictional) |
| NSI➣National Security Institute |
| NSI➣Nielsen Station Index |
| NSI➣Nutrition Screening Initiative |
| NSI➣Nuclear Surety Inspection |
| NSI➣National Statistical Institutes |
| NSI➣Nusantara Secom Infotech (Indonesia and Japan) |
| NSI➣Needle Stick Injury |
| NSI➣National Savings and Investments (UK) |
| NSI➣Network Solutions International (various locations) |
| NSI➣Not Seriously Ill |
| NSI➣Negative Social Impact (HIV/AIDS) |
| NSI➣National Student Index (New Zealand) |
| NSI➣Negative Self Image (psychology) |
| NSI➣Nomura Securities International |
| NSI➣Nu Skin International (Provo, UT) |
| NSI➣Never Stop Improving |
| NSI➣Naval Science Instructor |
| NSI➣National Service Life Insurance (US Navy) |
| NSI➣Non-Standard Installation (various companies) |
| NSI➣National Satellite Initiative (Canada) |
| NSI➣NASA Standard Initiator |
| NSI➣National Space Institute |
| NSI➣Nest Seekers International (real estate; various locations) |
| NSI➣Nutrition Santé International (French: Nutrition Health International) |
| NSI➣Network Side Interface (DOCSIS) |
| NSI➣Naval Station Ingleside (Ingleside, TX) |
| NSI➣Network Software Inspector (Secunia) |
| NSI➣Network Service Interface |
| NSI➣Non-Senate Instructional (various schools) |
| NSI➣National Strategies, Inc. (Washington, DC) |
| NSI➣Neurological Society of India |
| NSI➣Neighborhood Safety Initiative (various organizations) |
| NSI➣Nagios Status Information (computing) |
| NSI➣Not Signed In |
| NSI➣Yaounde, Cameroon - Nsimalen (Airport Code) |
| NSI➣Non-Standard Inference |
| NSI➣National Shipbuilding Initiative |
| NSI➣Net Satisfaction Index |
| NSI➣Next Sequential Instruction |
| NSI➣Non-Standard Neutrino Interactions |
| NSI➣Nuclear Safety Institute (est. 1990; Russia) |
| NSI➣Neurosurgery Institute (Russian Federation) |
| NSI➣Nonstandard Item |
| NSI➣Not Sufficient Information |
| NSI➣Nordisk Systemintegrering AB (Stockholm, Sweden) |
| NSI➣Nuclear Safety Inspection |
| NSI➣National Science Institute |
| NSI➣Name Server Interface |
| NSI➣New South Interactive |
| NSI➣Non-Serious Injury |
| NSI➣Negotiation Systems International |
| NSI➣Nonstocked Item |
| NSI➣Name Space Interface (Bellcore) |
| NSI➣Non Service Independent |
| NSI➣Newsprint South, Inc. |
| NSI➣No Suicidal Ideations (medicine) |
| NSI➣Northern Saline, Inc. |
| NSI➣Net Sales Income (finance) |
| NSI➣New Suspense Item |
| NSI➣Negative Social Imprinting (psychology) |
| NSI➣Numeric System Identifier |
| NSI➣Non-Specific Interferant (test result contaminants) |