Trace garment one found by empty grave (7)
I believe the answer is:
vestige
'trace' is the definition.
(synonyms)
'garment one found by empty grave' is the wordplay.
'garment' becomes 'vest' (vest is a type of garment or item of clothing).
'one' becomes 'i' (Roman numeral).
'found by' is a charade indicator (letters next to each other).
'empty' means to remove the middle letters.
'grave' with its centre removed is 'ge'.
'vest'+'i'+'ge'='VESTIGE'
(Other definitions for vestige that I've seen before include "A sign" , "what's left over" , "Give set for a surviving trace" , "Drop" , "Small remaining bit of what once was" .)