Ur·chin n.
1. Zool. A hedgehog.
2. Zool. A sea urchin. See Sea urchin.
3. A mischievous elf supposed sometimes to take the form a hedgehog. “We 'll dress [them] like urchins, ouphes, and fairies.”
4. A pert or roguish child; -- now commonly used only of a boy.
And the urchins that stand with their thievish eyes
Forever on watch ran off each with a prize. --W. Howitt.
You did indeed dissemble, you urchin you; but where's the girl that won't dissemble for an husband? --Goldsmith.
5. One of a pair in a series of small card cylinders, arranged around a carding drum; -- so called from its fancied resemblance to the hedgehog.
Urchin fish Zool., a diodon.