Nitrous is a slang term for nitrous oxide (N2O) also sometimes referred to as NOS. This misnomer most likely came about due to the abbreviation of the company name Nitrous Oxide Systems (NOS) - who were amongst those pioneers to develop systems for automotive performance use. More recently, the term was used in the Hollywood film "Fast and the Furious" , and not surprisingly, shortly after the film's release, various automotive newsgroups and forums featured unprecedented numbers of inquiries about "NOS" and how to install and use it.