This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
靽 combines 革 (leather) with 半, which likely contributes the sound. The exact historical development is uncertain, but it probably originally referred to a leather strap or tether.
The left side is leather 革, and the right side is half 半. Picture a leather strap cut in half, used to tie or bind something.
For ハン, imagine a leather strap used as a handcuff: hand -> ハン, and the leather binds tightly.