Fellow's initially entering minister's house (5)
I believe the answer is:
manse
'minister's house' is the definition.
(I've seen this before)
'fellow's initially entering' is the wordplay.
'fellow's' becomes 'mans' (man's).
'initially' says to take the initial letters.
The initial letter of 'entering' is 'e'.
'mans'+'e'='MANSE'
(Other definitions for manse that I've seen before include "Church minister's house" , "Ecclesiastical residence" , "Scottish minister's house" , "Names (anag.)" , "Untrue" .)