This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
釞 combines 金 (metal) with 入 (enter). The exact historical development is uncertain, and the character is rare.
The kanji visually contains metal 金 and enter 入, but its meaning is unclear. It may suggest something sharp entering metal, but this is speculative.
For チュウ, imagine a sharp metal tool making a 'chew' sound as it enters: chew -> チュウ, though the meaning is uncertain.