Disappointed, discouraged, or disheartened; having a fallen jaw as an expression of sadness or defeat.
From chap (to crack or strike, from Old Norse) or from chap (a fellow), combined with fallen—possibly meaning 'fallen-faced' or 'struck down,' though the exact evolution is debated among etymologists.
The word 'chapfallen' is a mystery—it might be a mondegreen (misheard mishap), originally from something else entirely, yet it perfectly captures disappointment because falling is what happens when your mouth drops in shock!
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