Pleasant entertaining English relative (5)
I believe the answer is:
niece
'relative' is the definition.
(type of relative)
'pleasant entertaining english' is the wordplay.
'pleasant' becomes 'nice' (similar in meaning).
'entertaining' is an insertion indicator (inviting in, as for dinner).
'english' becomes 'E' (abbreviation).
'nice' enclosing 'e' is 'NIECE'.
(Other definitions for niece that I've seen before include "Family relation" , "[PRIEST'S] daughter?" , "Young female relative" , "A younger female relative" , "Female family member" .)