This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
掕 combines 扌 (hand) with 夌, which likely contributes a sound element. The exact historical development is uncertain.
The hand radical 扌 beside 夌 suggests an action, but the specific meaning is unclear. Imagine a hand doing something precise or stopping motion, based on the kun reading とめる.
For リョウ, imagine a hand stopping a rolling log: the log rolls (ロウ) but the hand stops it, cueing リョウ.