The car commuter knows he'll get it tomorrow (3)
I believe the answer is:
jam
'the car commuter knows he'll get it tomorrow' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for jam that I've seen before include "Spread; improvise (jazz)" , "Preserve; pack tightly" , "Troublesome situation" , "awful traffic" , "problem" .)