Complete: that's gross money (5)

I believe the answer is:

dough

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'money' is the definition.
(dough can informally mean money)

'complete that's gross' is the wordplay.
'complete' becomes 'do' (doing is a kind of completing).
'that's gross' becomes 'ugh' (I am not sure about this - if you are sure you should believe this answer much more).
'do'+'ugh'='DOUGH'

Can you help me to learn more?

(Other definitions for dough that I've seen before include "Paste; money" , "Money (sl.)" , "Moistened flour" , "Uncooked bread - money" , "Money (slang)" .)

I've seen this clue in The Telegraph.

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