What keeps the cockney diner warm? (6)
I believe the answer is:
heater
'what keeps the cockney' is the definition.
I can't tell whether this defines the answer.
'diner warm?' is the wordplay.
I cannot quite understand how this works, but
'diner' could be 'eater' (to dine is to eat a meal) and 'eater' is located in the answer.
A single letter 'h' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for heater that I've seen before include "Warming device" , "Room warmer" , "fire" , "Source of warmth; gun" , "Radiator" .)