Right component
㕣 — ⿱
八 口, a stream coursing into a basin. Supplies the sound:
㕣 yǎn → chuán through Old Chinese sound shift, no longer transparent but the same phonetic appears in
沿 (follow along) and
铅 (lead metal). Adds a faint semantic of water flowing in a channel — appropriate for a boat moving down a river.
