Garments in new chest: look inside (7)
I believe the answer is:
clothes
'garments' is the definition.
('clothe' can be a synonym of 'garment')
'new chest look inside' is the wordplay.
'new' indicates an anagram.
'look' becomes 'lo' (archaic exclamation meaning 'look!').
'inside' is an insertion indicator.
'chest' with letters rearranged gives 'cthes'.
'cthes' enclosing 'lo' is 'CLOTHES'.
'in' is the link.
(Other definitions for clothes that I've seen before include "Gear" , "Worn items" , "Raiment" , "Items of apparel" , "Attire" .)