Nos

Nos is a term that appears in different domains with distinct meanings. In Latin, nos is the first-person plural pronoun meaning "we" or "us," used as the object or subject in classical texts. In French, nos is a possessive determiner meaning "our," used before plural nouns.

As an acronym, NOS has several technical and organizational meanings. Network Operating System refers to an operating system designed to support networking of multiple computers and shared resources. Nitrous Oxide System, commonly abbreviated NOS, describes aftermarket devices that inject nitrous oxide into internal combustion engines to increase power, particularly in auto racing—usage is regulated or restricted in many jurisdictions. Nitric Oxide Synthase is an enzyme family that produces nitric oxide, a signaling molecule; isoforms include neuronal, inducible, and endothelial NOS.

Not Otherwise Specified is a coding qualifier used in medical classifications when a diagnosis cannot be more precisely described. National Ocean Service is a United States federal agency within NOAA focused on oceans, coasts, and estuarine resources. New Old Stock is retail jargon for inventory that is new but no longer sold, often discontinued items or vintage goods.

NOS is thus a polysemous term whose meaning is determined by capitalization and field. In context, it can refer to language forms, software, automotive technology, biochemistry, medicine, government agencies, or retail inventory.