shut up
鉗 centers on forcibly silencing or restraining speech: to shut someone up, often through a physical clamp or gag. The idea extends to any act of suppressing expression.
鉗 combines 金 (metal) with 甘, which likely contributes the sound. The character originally referred to metal tongs or a clamp used to hold or silence, hence the meaning 'shut up'.
Metal 金 is used to clamp something sweet 甘 shut. Imagine a metal gag silencing a sweet talker.
For ケン, picture a metal clamp silencing someone named Ken: Ken -> ケン, and the metal gag shuts him up.