Foreign seaman - an awful rascal (6)
I believe the answer is:
lascar
'foreign seaman' is the definition.
'lascar' can be an answer for 'seaman' (I've seen this before). I'm not sure about the 'foreign' bit.
'awful rascal' is the wordplay.
'awful' is an anagram indicator.
'rascal' anagrammed gives 'LASCAR'.
'an' acts as a link.
Can you help me to learn more?
(Other definitions for lascar that I've seen before include "The East Indian sailor is a rascal" , "Kind of foreign sailor - quite a rascal" , "Asian sailor" , "Indiaman Jack" , "Eastern sailor" .)