This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
韗 combines 韋 (leather) and 軍 (army), likely referring to leather military equipment such as boots or armor. The exact historical development is uncertain.
The left side 韋 suggests leather, and the right side 軍 suggests military. Picture a soldier's leather boot or piece of armor, though the exact meaning is uncertain.
For ウン, imagine a leather boot making an 'oon' sound when it hits the ground: oon -> ウン, like a heavy military boot.