Call for errand boy (4)
I believe the answer is:
page
This clue is a double definition.
'call for' is the first definition.
(to page is to call with a pager)
'errand boy' is the second definition.
(I know that page is a type of errand boy)
(Other definitions for page that I've seen before include "contribution to book?" , "Attendant - this is on one!" , "Side" , "Boy at match" , "one seeking knighthood" .)