collapse
獘 centers on collapse or ruin, often in a destructive or fatal sense. The single given meaning 'collapse' is the core idea.
獘 combines 敝 (worn out, ruined) and 犬 (dog), suggesting a dog that is worn out or collapsing. The exact historical development is uncertain, but the components point to ruin or collapse.
A worn-out, tattered dog (敝 + 犬) finally collapses from exhaustion.
For ヘイ, imagine the dog collapsing with a heavy 'hey' sigh: hey -> ヘイ.
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