Muffler can leave a permanent mark on fingertip (5)
I believe the answer is:
scarf
'muffler' is the definition.
(I've seen this in another clue)
'leave a permanent mark on fingertip' is the wordplay.
'leave a permanent mark on' becomes 'scar' (I've seen this in another clue).
'fingertip' becomes 'f' (this could be a standard abbreviation I've not previously seen).
'scar'+'f'='SCARF'
'can' is the link.
Can you help me to learn more?
(Other definitions for scarf that I've seen before include "Winter wear" , "item of clothing" , "Neck covering" , "Neck/head garment" , "Garment worn around head or neck" .)