Very frightened by the corpse! (6,5)
I believe the answer is:
scared stiff
'very' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'frightened by the corpse' is the wordplay.
'frightened' becomes 'scared' (scared means frightened or fearful).
'by' says to put letters next to each other.
'the corpse' becomes 'stiff' (synonyms).
'scared'+'stiff'='SCARED STIFF'
Can you help me to learn more?
(Other definitions for scared stiff that I've seen before include "Frightened to death!" , "Petrified" .)