os meaning and definition

OS noun

Definition of os (noun)

1. a mouth or mouthlike opening
2. a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
   • synonyms: atomic number 76, osmium
3. (computer science) software that controls the execution of computer programs and may provide various services
   • synonyms: operating system
4. the left eye
   • synonyms: oculus sinister
5. rigid connective tissue that makes up the skeleton of vertebrates
   • synonyms: bone