Wax sticks and runs until hot becomes cold (7)
I believe the answer is:
candles
'wax sticks' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps there's a link between them I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for candles that I've seen before include "They illuminate" , "Tealights, for example" , "Wax lights" , "They're held by sconces" , "Sticks of wax with wicks" .)