sigh in disapproval, take small
嘰 centers on a vocal expression of mild criticism or discontent: sighing in disapproval. The sense of 'take small' is a rare, possibly archaic extension that may not share a clear conceptual link with the sighing meaning.
嘰 combines 口 (mouth) with 幾, which likely contributes the sound. The exact historical development is uncertain, but the structure suggests a phono-semantic compound where the mouth radical indicates a vocal action.
The mouth 口 on the left and the complex 幾 on the right can be seen as a mouth making a small, disapproving sound. Imagine someone clicking their tongue softly in disapproval.
For キ, picture a person sighing 'key...' in a high-pitched, disapproving tone: key -> キ, and the sound comes from the mouth 口.
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