This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
滽 combines 氵 (water) with 庸, which likely contributes the sound. The exact historical development is uncertain.
The water radical 氵 beside 庸 suggests something related to water, but the specific meaning is uncertain. Picture a forgotten river name written with this character.
For ヨウ, imagine a yawning river: yawn -> ヨウ, and the water 氵 flows lazily beside the 庸 component.
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