noun, noun or participle which takes 'suru'
going around; orbiting; circling
Refers to the action of moving around something, such as a track, orbit, or circuit. Often used in contexts like racing, satellites, or patrols.
人工衛星が地球を周回している。
The satellite is orbiting the Earth.
ランナーはトラックを10周回
The runner went around the track ten times.
noun
circumference; girth; surroundings
Refers to the distance around something or the area surrounding it. Less common than sense 1; often replaced by 周囲 (しゅうい) in modern Japanese.
この湖の周回は約5キロメートルだ。
The circumference of this lake is about five kilometers.