Crew's quarters for English man on board (10)
I believe the answer is:
forecastle
'crew's quarters' is the definition.
(part of a ship including crew's quarters)
'for english man on board' is the wordplay.
'english' becomes 'e' (abbreviation).
'man on board' becomes 'castle' (man can mean a chess piece).
'for'+'e'+'castle'='FORECASTLE'
(Other definitions for forecastle that I've seen before include "section of the ship" , "Crew's quarters in bow of ship" , "where the crew is housed" , "Fo'c'sle in full" , "ship's living quarters" .)