This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form combines 氵 (water) with 翼, but the original semantic and phonetic roles are unclear.
The water radical 氵 beside 翼 (wing) might suggest water flowing like wings, but the meaning is too uncertain for a reliable mnemonic.
For ヨク, imagine a yoke floating on water: yoke -> ヨク, though the kanji's meaning is unclear.