Foreign sailor left a mark (6)
I believe the answer is:
lascar
'foreign sailor' is the definition.
'lascar' can be an answer for 'sailor' (lascar is a kind of sailor). I am not sure about the 'foreign' bit.
'left a mark' is the wordplay.
'left' becomes 'l' (common abbreviation).
'mark' becomes 'scar' (mark left by an injury).
'l'+'a'+'scar'='LASCAR'
Can you help me to learn more?
(Other definitions for lascar that I've seen before include "Indiaman Jack" , "Rascal (anag) - oriental seaman" , "E. Indian seaman" , "Asian sailor" , "Camp-follower" .)