This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
膮 combines ⺼ (meat/flesh) with 堯, which likely contributes the sound. The exact historical development is uncertain, and the modern form may be a simplification.
The left side ⺼ suggests something related to the body or flesh, but the overall meaning is obscure. Picture a mysterious meat dish (あつもの) that is hard to identify.
For キョウ, imagine a chef in Kyoto (キョウ) preparing an unknown meat stew: Kyoto -> キョウ, and the stew is the kanji's obscure meaning.