Look for a follower of Nanak, we hear (4)
I believe the answer is:
seek
'look for' is the definition.
(I know that look for can be written as seek)
'a follower of nanak we hear' is the wordplay.
'a follower of nanak' becomes 'sikh' (I've seen this in another clue).
'we hear' shows a homophone (sound like).
'sikh' is a homophone of 'SEEK'.
(Other definitions for seek that I've seen before include "Try to locate or reach" , "Attempt - search" , "Try to find" , "Hunt, look for" , "Go looking for" .)