He is out of line (4)
I believe the answer is:
neil
'he' is the definition.
'out of line' is the wordplay.
'out of' indicates an anagram.
'line' with letters rearranged gives 'NEIL'.
'is' acts as a link.
(Other definitions for neil that I've seen before include "- Armstrong, first man to set foot on the Moon" , "-- Sedaka, US singer" , "One of 14 DIAMONDS] 's" , "-- Armstrong, Apollo astronaut" , "- Armstrong, first man to walk on the moon" .)