Van Gogh was halfway to being this brave, having lost head (7)
I believe the answer is:
earless
'van gogh was halfway to being this brave having lost head' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I don't see?
'this brave having lost head' is the wordplay.
'this brave' becomes 'fearless' (I've seen this before).
'having lost head' means to remove the first letter.
'fearless' with its initial letter taken away is 'EARLESS'.
Can you help me to learn more?
(Other definitions for earless that I've seen before include "apparently deaf?" , "Lugs missing" , "Seals appear so" , "Like some seals" , "not listening then?" .)