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
abbr. [美]航天科学局（Office of Space Sciences）；[美]战略情报局（Office of Strategic Services）