Octopus originally caught in net close to home left with a sad expression (9)

I believe the answer is:

woebegone

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But I can't explain it at all! Could you help me understand?

(Other definitions for woebegone that I've seen before include "Miserable in appearance" , "Miserable-looking" , "Sad, miserable" , "crestfallen" , "Unhappy" .)

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