Nobody's free to swap spectacles for monocle 'by right' (5)

I believe the answer is:

loser

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'nobody's' is the definition.
(both can mean an unsuccessful person)

I don't understand the remainder of the clue.

(Other definitions for loser that I've seen before include "Defeated contestant" , "One not winning" , "Unsuccessful contestant" , "One who is (always) unsuccessful" , "sad type?" .)

I've seen this clue in The Independent.

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