os
os
- n a mouth or mouthlike opening
- n a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
- n (computer science) software that controls the execution of computer programs and may provide various services
- n the left eye
- n rigid connective tissue that makes up the skeleton of vertebrates
- n a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
- n the 15th letter of the Roman alphabet
- n the blood group whose red cells carry neither the A nor B antigens