ora

名词 os:

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

o.ra

n.（名词）
Plural of os
os的复数