UnixPronunciation: /ˈjuːnɪks/Definition of Unix noun [mass noun] Computing, trademark an operating system analogous to DOS and Windows, supporting multiple concurrent users: [as modifier]:software for Unix systemsOrigin: 1970s: from uni- 'one' + a respelling of -ics, on the pattern of an earlier less compact system called MulticsUnix in other Oxford dictionaries Definition of Unix in the US English dictionary