1) An acronym for the brand name 'Nitrous Oxide Systems'. NOS produces a chemical known as nitrous oxide, often used in the performance optimization of car and motorcycle engines. The chemical (N2O) breaks up upon contact with air, releasing extra oxygen into the engine.any misconceptions have arisen from the term NOS, particularily founded by the film i The Fast And The Furious /i. One misconception is that NOS can be installed on any car, and with the push of a button it will result in an exponential gain in speed. Another is that NOS i is /i nitrous oxide; NOS is only a brand name.