Barber's shout (4)
I believe the answer is:
next
'barber's shout' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for next that I've seen before include "Neighbour lives in the house . . . . door" , "Coming nearest in time or sequence" , "Immediately following in time or order" , "The one following or adjacent" , "Retailer" .)