Pardoned construction of grave (7)
I believe the answer is:
forgave
'pardoned' is the definition.
(I've seen this before)
'construction of grave' is the wordplay.
'construction' is an anagram indicator (answer constructed from certain letters).
'of'+'grave'='ofgrave'
'ofgrave' is an anagram of 'FORGAVE'.
(Other definitions for forgave that I've seen before include "Let off" , "overlooked" , "Excused (an offence)" , "Pardoned" .)