Spiky little one plays mischievously on the streets. (6)
I believe the answer is:
urchin
'spiky little' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for urchin that I've seen before include "kid on street" , "Grubby boy or sea plant" , "Poor city child" , "Marine hedgehog" , "Hedgehog - ragamuffin" .)