Fold note in suit (6)
I believe the answer is:
crease
'fold' is the definition.
('crease' can be a synonym of 'fold')
'note in suit' is the wordplay.
'note' becomes 're' (**).
'in' is an insertion indicator.
'suit' becomes 'case' ('case' can be a synonym of 'suit').
're' going inside 'case' is 'CREASE'.
(Other definitions for crease that I've seen before include "feature of smart trousers" , "Fold, maybe unmeant" , "Cricket pitch marking" , "Furrow; cricket line" , "Line on a cricket pitch" .)