Endless city rush for fruit (6)
I believe the answer is:
citrus
'for fruit' is the definition.
(citrus is a kind of fruit)
'endless city rush' is the wordplay.
'endless' means to remove the last letter.
'rush' becomes 'rus' (I can't explain this - if you can you should give a lot more credence to this answer).
'city' with its final letter removed is 'cit'.
'cit'+'rus'='CITRUS'
Can you help me to learn more?
(Other definitions for citrus that I've seen before include "Orange or lemon tree, perhaps" , "Lemon genus" , "Type of tree bearing acidic fruit" , "Fruit from orange or lemon tree" , "Describing lemons, for example" .)