This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
匤 is a rare character whose historical origin is uncertain. It visually combines 匚 (box) with 玉 (jewel), but whether this reflects a true semantic or phonetic structure is unclear.
The outer 匚 looks like a container, and inside is 玉 (jewel). Imagine a box holding a precious jewel, but remember that the actual meaning of this rare kanji is unclear.
For キャク, imagine a jewel box that makes a sharp 'kyak' sound when it snaps shut: kyak -> キャク, and the box holds the jewel.