swing
鞦 centers on a swinging motion, specifically referring to a swing or the act of swinging.
鞦 combines 革 (leather) with 秋 (autumn), likely as a phono-semantic compound where 秋 contributes the sound and 革 indicates a leather object related to swinging, such as a swing or a strap.
Leather (革) straps hanging from an autumn (秋) tree form a swing. Picture a leather swing swaying under golden autumn leaves.
For シュウ, imagine a shoe (シュー) tied to a leather swing, but with a slight twist: the swing goes 'shoo' as it arcs, and you remember it's シュウ, not just シュー. The leather swing makes a 'shoo' sound in the autumn breeze.
crupper