Thick slice of bread (8)
I believe the answer is:
doorstep
'thick slice of bread' is the definition.
(term for a large or thick slice of bread)
This is the entire clue.
(Other definitions for doorstep that I've seen before include "To conduct house-to-house interviews" , "Go from house to house" , "substantial amount of bread" , "sliced bread" , "big piece of bread" .)