Strange wretch is holding out for the most part (7)
I believe the answer is:
curious
'strange' is the definition.
('curious' can be a synonym of 'strange')
'wretch is holding out for the most part' is the wordplay.
'wretch' becomes 'cur' (I've seen this before).
'holding' indicates putting letters inside.
'for the most part' means to remove the last letter.
'out' with its last letter taken off is 'ou'.
'is' placed around 'ou' is 'ious'.
'cur'+'ious'='CURIOUS'
(Other definitions for curious that I've seen before include "Unusual; eager to learn" , "Strange - inquisitive" , "Eager to know something, perhaps nosy" , "Questioning" , "with a great deal of interest!" .)