Bits of litter spread over street (5)
I believe the answer is:
runts
'bits of litter' is the definition.
Although both the answer and definition are plural nouns, I can't see how they can define each other.
'spread over street' is the wordplay.
'spread' becomes 'run' (running is a kind of spreading).
'over' says the letters should be written in reverse.
'street' becomes 'st' (abbreviation).
'st' written backwards gives 'ts'.
'run'+'ts'='RUNTS'
Can you help me to learn more?
(Other definitions for runts that I've seen before include "Smallest of litters" , "Small pigs" , "Small piglets" , "Littlest pigs" , "Smallest animals in a litter" .)