moult samarium
This rare kanji has no clear standalone meaning. The given glosses "moult samarium" are obscure and do not form a coherent conceptual center. Treat its meaning as uncertain.
鎩 combines 金 (metal) with 殺, which likely contributes the sound. The exact historical development and original meaning are uncertain.
The left side is metal 金, and the right side is 殺 (kill). Picture a metal tool that kills or strips away, like a blade used for moulting or scraping, but the connection to samarium is unclear.
For サイ, imagine a sigh of relief as a metal blade finishes moulting: sigh -> サイ, though the meaning is obscure.