Announce an errand boy (4)
I believe the answer is:
page
I believe this is a double definition.
'announce' is the first definition.
(thesaurus)
'an errand boy' is the second definition.
(page is a kind of errand boy)
(Other definitions for page that I've seen before include "Young attendant for part of a book" , "Sheet of book" , "Piece of paper for a young attendant" , "a significant bit of history?" , "Young hotel employee" .)