Seaman with a friend and many more (7)
I believe the answer is:
matelot
'seaman' is the definition.
(thesaurus)
'with a friend and many more' is the wordplay.
'with' is a charade indicator (letters next to each other).
'a friend' becomes 'mate' (mate is a kind of friend).
'and' means one lot of letters go next to another.
'many' becomes 'l'.
'more' becomes 'ot' (I can't explain this - if you can you should give a lot more credence to this answer).
'mate'+'l'='matel'
'matel' put next to 'ot' is 'MATELOT'.
Can you help me to learn more?
(Other definitions for matelot that I've seen before include "A lot met (anag) - sailor" , "One at sea" , "seafarer" , "Rating" , "Sailor (slang from French)" .)