She entertains those at sea in front of ship (7)
I believe the answer is:
hostess
'she entertains' is the definition.
(I've seen this before)
'those at sea in front of ship' is the wordplay.
'at sea' is an anagram indicator.
'in front of' says to put letters next to each other.
'ship' becomes 'ss'.
'those' anagrammed gives 'hoste'.
'hoste'+'ss'='HOSTESS'
(Other definitions for hostess that I've seen before include "party organiser" , "who welcomes guests?" , "Lady with guests" , "Plane stewardess" , "Aircraft stewardess" .)