circumference, circuit, lap
周 centers on a closed path around something: a circumference, a circuit, or a lap. The idea is always a boundary or route that goes around and returns.
周 originally depicted a border or enclosure around a field, representing a perimeter or circuit. The modern form combines 用 (an enclosure) with 口 (mouth or opening), suggesting a defined surrounding area.
The outer frame 用 is like a fence, and the inner 口 is the area inside. Picture a running track: the fence marks the circumference, and the inner field is where the lap is completed.
For シュウ, imagine running a circuit and shouting 'Shoo!' as you complete each lap: 'Shoo!' -> シュウ, tying the sound to the circular motion.
counter for laps or circuits
circumference; girth
circumference; outskirts; environs; around; in the area of; in the vicinity of
surroundings; environs
frequency (esp. of waveforms)
one round; one circuit; one revolution; one lap; one turn
going around; orbiting; circling
cycle; period
common knowledge; being well-known; making (something) well-known
cycle; wave; frequency
outer circumference; perimeter
circumference
(circular) tour; round trip; excursion
Suō (former province located in the southeast of present-day Yamaguchi Prefecture)
high frequency; HF
careful; thorough; meticulous; scrupulous
fringe; rim; periphery; borders; outskirts
semicircle; hemicycle; half globe
circumnavigation; circle tour by ship
second time around; second lap