This character is rare and is used almost only in personal names.
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铖 has no general dictionary meaning and is not used as a word. It exists almost entirely as a given-name character, chosen for the lucky sound chéng (suggesting 成 'success') plus the solid 'metal' radical.
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Name-character only — you will only meet 铖 in people's names, not in ordinary text.
The left-side metal radical 钅 (squeezed form of 金) puts 铖 among metal characters. In name use it adds a sense of strength and solidity rather than a literal metal.
Right side 成 supplies the sound chéng directly with no tone change, and its 'succeed / accomplish' meaning is exactly why parents pick this character for a name — a built-in lucky connotation.