bird
鳷 centers on a specific kind of bird. The given meaning is simply 'bird', so treat it as a rare character for a bird species.
鳷 combines 支 (likely a phonetic component) with 鳥 (bird), suggesting a specific bird name. The exact historical development is uncertain.
A bird 鳥 with a branch-like 支 shape beside it: imagine a rare bird perched on a branch.
For シ, picture the bird sitting silently on the branch: the 'sh' of silence cues シ, and the bird stays still.
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