Such a lot is no fortune! (3)

I believe the answer is:

fat

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'such' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?

I can't explain the rest of the clue.

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(Other definitions for fat that I've seen before include "Obese, having spare tyre etc" , "As Bunter" , "Cooking grease" , "Corpulent; little (chance)" , "Adipose tissue" .)

I've seen this clue in the Evening Standard.

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