Resort in which you'll find English relative (5)
I believe the answer is:
niece
'relative' is the definition.
(type of relative)
'resort in which you'll find english' is the wordplay.
'resort' becomes 'nice' (French coastal resort).
'in which you'll find' is an insertion indicator.
'english' becomes 'E' (abbreviation as in OED).
'nice' going around 'e' is 'NIECE'.
(Other definitions for niece that I've seen before include "Brother's daughter" , "A sibling's child" , "Female family member" , "Criminal" , "Family relation" .)