Gold crockery starts to level off (7)
I believe the answer is:
plateau
'level off' is the definition.
(I've seen this in another clue)
'gold crockery starts' is the wordplay.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'crockery' becomes 'plate' (plate is a kind of crockery).
'starts' means one lot of letters go next to another.
'au' after 'plate' is 'PLATEAU'.
'to' acts as a link.
(Other definitions for plateau that I've seen before include "Paul, eat! (anag)" , "hat" , "Flat highland" , "Large level tract of elevated land" , "plane" .)