Hard bread (4)
I believe the answer is:
rusk
'hard bread' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rusk that I've seen before include "It's hard for babe to get teeth into" , "Baby's dry biscuit" , "Baby biscuit" , "Bread baked for babies" , "Hard crisp baby food" .)