Was Rachmaninoff so prone to kleptomania? (5-8)

I believe the answer is:

light-fingered

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'prone to kleptomania?' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for light-fingered that I've seen before include "Liable to steal" , "Like a pickpocket" , "Having a propensity for stealing" , "Given to thieving" , "Adept at thieving" .)

I've seen this clue in The Independent.

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