Word.ws English Dictionary

OS X

UK/əʊˌɛsˈtɛn/US/oʊˌɛsˈtɛn/

OS X proper noun: former name of macOS; itself formerly known as Mac OS X.

Proper noun

OS X

  1. (trademark) Former name of macOS; itself formerly known as Mac OS X.

Origin of OS X

Ellipsis of Mac OS X; from OS (“operating system”) + X (“ten”, Roman numeral), as a successor to Mac OS 9.

Questions about OS X

What does OS X mean?
OS X means former name of macOS; itself formerly known as Mac OS X.
What part of speech is OS X?
OS X is a proper noun.
How do you pronounce OS X?
OS X is pronounced /əʊˌɛsˈtɛn/ (UK).

Words near OS X in the dictionary

  1. OS nappy
  2. os paracuneiforme
  3. os penis
  4. os trapezoideum
  5. os trochleare calcanei
  6. OS X
  7. OS&D
  8. OS&Y
  9. OS&Ys
  10. os-
  11. OS-specific

Source and license

Adapted from Wiktionary: OS X (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “OS X.” Word.ws, https://word.ws/os_x. Based on Wiktionary, CC BY-SA 4.0.