pheasant
鷊 centers on a specific bird: the pheasant. It is a narrow, concrete term for this type of fowl.
鷊 combines 鳥 (bird) with 鬲, which likely contributes the sound. The character was created to name a specific bird, the pheasant.
The left side 鬲 looks like a stylized bird's crest or elaborate plumage, while the right side 鳥 confirms it's a bird. Together they point to a fancy bird: a pheasant.
For ゲキ, imagine a pheasant giving a loud, sharp cry that sounds like 'geki!' as it bursts from the underbrush.
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