This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
趐 combines 走 (run) with 羽 (feathers). The exact historical development is uncertain, but it likely relates to swift or light movement.
The kanji shows running 走 with feathers 羽 inside. Imagine a bird running so fast its feathers blur, suggesting swift movement.
For ケツ, imagine a runner with feathered shoes who suddenly gets a kets (a made-up sound like a quick, sharp breath) as they sprint: kets -> ケツ.