NSA means lets have some fun without creating any obligations beyond the moment. We do what we do tonight and dont ever have to see each other again. This Internet Slang page is designed to explain what the meaning of NSA is. The slang word / acronym / abbreviation NSA means . Internet Slang. A list of. No Strings Attached sounds like a simple concept, but what does it really mean? It could mean different things to different people as there are.