Fleece man on board (4)
I believe the answer is:
rook
I believe this is a double definition.
'fleece' is the first definition.
(thesaurus)
'man on board' is the second definition.
(chess)
(Other definitions for rook that I've seen before include "man on board" , "Poignant, evocative" , "Gregarious black bird" , "Defraud; bird; chessman" , "Rip off - bird" .)