This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
弜 is composed of two 弓 (bow) components side by side. The exact historical development is uncertain, but it likely relates to the idea of a strong or doubled bow.
Two bows 弓弓 placed together suggest something reinforced or doubled in strength, like a bow that is extra strong.
For キョウ, imagine a strong bow that makes a loud 'kyong' sound when released: kyong -> キョウ, and the doubled bows 弜 amplify the power.