Original meaning: to carve jade

Depicts a carved jade object, now written as 彫/琱. The meaning later shifted to "circumference" and "cycle". Later the 口 component was added when 周 was used to refer to a geographical region to indicate that the character was only "mouthed", i.e. used for its sound. In simplified Chinese 周 is also used to mean "week", while in traditional Chinese this meaning is written with a separate character 週.