Fancy cloak worn by wealthy shortened (7)
I believe the answer is:
caprice
'fancy' is the definition.
(thesaurus)
'cloak worn by wealthy shortened' is the wordplay.
'cloak' becomes 'cape' (cape is a kind of cloak).
'worn by' means one lot of letters goes inside another (I've seen this in other clues).
'wealthy' becomes 'rich' ('rich' can be similar in meaning to 'wealthy').
'shortened' means to remove the last letter.
'rich' with its final letter taken off is 'ric'.
'cape' placed around 'ric' is 'CAPRICE'.
(Other definitions for caprice that I've seen before include "A whim, or piece of music in lively fanciful style" , "'Impulse, whim (7)'" , "unaccountable change" , "Sudden mood change" , "Sudden change of mind" .)