A wound mark permitted to be red! (7)
I believe the answer is:
scarlet
'be red' is the definition.
(synonyms)
'a wound mark permitted' is the wordplay.
'a wound mark' becomes 'scar' (I've seen this in another clue).
'permitted' becomes 'let' (to let something happen is to permit it).
'scar'+'let'='SCARLET'
'to' is the link.
(Other definitions for scarlet that I've seen before include "immoral" , "bloody?" , "Cherry-red" , "Vivid red" , "Murderer" .)