Heal as bones knight protected with outfit (4)
I believe the answer is:
knit
'heal as bones' is the definition.
(I've seen this in another clue)
'knight protected with outfit' is the wordplay.
I cannot quite understand how this works, but
'knight' could be 'n' (chess abbreviation) and 'n' is found within the answer.
'outfit' could be 'kit' (kitting is a kind of outfiting) and 'kit' is present in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for knit that I've seen before include "Make woollen garments" , "get together" , "Become joined" , "Use needles to make clothes" , "mesh" .)