Intern in NI town welcoming English rector (7)
I believe the answer is:
learner
'intern' is the definition.
(intern can mean a trainee or novice)
'ni town welcoming english rector' is the wordplay.
'ni town' becomes 'larne' (I've seen this before).
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'english' becomes 'E' (abbreviation).
'rector' becomes 'r'.
'larne' going around 'e' is 'learne'.
'learne'+'r'='LEARNER'
'in' acts as a link.
(Other definitions for learner that I've seen before include "He displays the L-plate" , "Student (of driving?)" , "Trainee (driver)" , "New 17 across" , "Tyro" .)