Garment somehow wrong not right (4)
I believe the answer is:
gown
'garment' is the definition.
(I know that gown is a type of garment)
'somehow wrong not right' is the wordplay.
'somehow' indicates anagramming the letters.
'not' is a deletion indicator.
'right' becomes 'r' (common abbreviation).
'wrong' with 'r' taken away is 'wong'.
'wong' anagrammed gives 'GOWN'.
(Other definitions for gown that I've seen before include "Shift" , "Academic or formal dress" , "Academic attire" , "Woman's long dress or judge's robe" , "Dress for formal occasions" .)