Hammer makes set flat (7)
I believe the answer is:
pancake
'flat' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'hammer makes set' is the wordplay.
I cannot really understand how this works, but
'hammer' could be 'pan' (I've seen this before) and 'pan' is located in the answer.
'set' could be 'cake' (I've seen this in another clue) and 'cake' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pancake that I've seen before include "Theatrical make-up; fried batter" , "F" , "Flat delicacy popular on Shrove Tuesday" , "Shrove Tuesday food for flippers" , "Flat fried cake" .)