Niggard who would be sad if able (5)

I believe the answer is:

miser

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'niggard' is the definition.
(synonyms)

I don't understand how the remainder of the clue works.

(Other definitions for miser that I've seen before include "One doesn't spend much" , "Stingy person like Scrooge" , "Mean-minded type" , "Curmudgeon" , "auger" .)

I've seen this clue in The Globe and Mail.

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