King who was hard-hearted when badly hurt? (6)
I believe the answer is:
arthur
'king who was hard-hearted' is the definition.
'arthur' can be an answer for 'king' (I've seen this before). I'm not certain of the rest of the definition.
'when badly hurt?' is the wordplay.
'when' becomes 'ar' (I can't justify this - if you can you should give a lot more credence to this answer).
'badly' indicates an anagram.
'hurt' anagrammed gives 'thur'.
'ar'+'thur'='ARTHUR'
Can you help me to learn more?
(Other definitions for arthur that I've seen before include "Greed" , "Old king" , "Excalibur king" , "Legendary British king" , ""The once and future king"" .)