Explosion half buried a good man (5)
I believe the answer is:
burst
'explosion' is the definition.
(I know that explosion can be written as burst)
'half buried a good man' is the wordplay.
'half' indicates taking half.
'a good man' becomes 'st' (abbreviation for saint).
'buried' halved is 'bur'.
'bur'+'st'='BURST'
(Other definitions for burst that I've seen before include "Crack" , "Split asunder" , "Be very full (with)" , "Explosion" , "Puncture, explode" .)