French resort entertaining eastern relation (5)
I believe the answer is:
niece
'relation' is the definition.
(I know that relation can be written as niece)
'french resort entertaining eastern' is the wordplay.
'french resort' becomes 'nice' (French coastal resort).
'entertaining' indicates putting letters inside.
'eastern' becomes 'e'.
'nice' placed around 'e' is 'NIECE'.
(Other definitions for niece that I've seen before include "A sibling's child" , "Family relation" , "Son's cousin" , "A sibling's daughter" , "Female family member" .)