One dropping pound, picked up and pocketed by smoker (7)

I believe the answer is:

fumbler

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'one dropping' is the definition.
(someone who fumbles or drops things)

I cannot understand how the remainder of the clue works.

(Other definitions for fumbler that I've seen before include "one inept at sport" , "Inept person" , "Clumsy person" .)

I've seen this clue in The Guardian.

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