grosbeak, hawkfinch, (kokuji)
鵤 is a kokuji (Japanese-made kanji) that names specific finch-like birds: the grosbeak and the hawkfinch. Its meaning is tied to those particular bird species.
鵤 is a kokuji created in Japan by combining 角 (horn) and 鳥 (bird), likely referring to the horn-like beak shape of the grosbeak or hawkfinch.
A bird (鳥) with a horn (角) on its beak: that distinctive thick, horn-colored beak belongs to a grosbeak or hawkfinch.
For いかる, imagine a grosbeak angrily shouting 'Icarus!' as it flies too close to the sun: Icarus -> いかる, and the bird's horn-like beak makes it look like a tiny mythological creature.
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