This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鋡 combines 金 (metal) with 含, which likely contributes the sound. The exact historical development is uncertain.
The metal radical 金 suggests something metallic, but the overall meaning is unclear. Picture a mysterious metal object with an unknown purpose.
For カン, imagine a can made of metal: can -> カン, and the metal radical 金 reinforces the image.