A beating to mark the skin (6)
I believe the answer is:
tattoo
This clue could be a double definition.
'a beating' is the first definition.
(thesaurus)
'mark the skin' is the second definition.
'tattoo' can be an answer for 'mark' (thesaurus). I am not certain of the 'the skin' bit.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for tattoo that I've seen before include "display involving military band" , "one has to beat" , "Skin inking" , "Design worked on skin" , "drawing on arms, perhaps" .)