(Zool.) Any one of numerous species of echinoderms of the order Echinoidea. When living they are covered with movable spines which are often long and sharp. [ 1913 Webster ]

n. [ OE. urchon, irchon, a hedgehog, OF. ireçon, eriçon, heriçon, herichon, F. hérisson, a derivative fr. L. ericius, from er a hedgehog, for her; akin to Gr. chh`r. Cf. Herisson. ] [ 1913 Webster ]

1. (Zool.) A hedgehog. [ 1913 Webster ]

2. (Zool.) A sea urchin. See Sea urchin. [ 1913 Webster ]

3. A mischievous elf supposed sometimes to take the form a hedgehog. “We 'll dress [ them ] like urchins, ouphes, and fairies.” Shak. [ 1913 Webster ]

4. A pert or roguish child; -- now commonly used only of a boy. [ 1913 Webster ]

And the urchins that stand with their thievish eyes
Forever on watch ran off each with a prize. W. Howitt. [ 1913 Webster ]

You did indeed dissemble, you urchin you; but where's the girl that won't dissemble for an husband? Goldsmith. [ 1913 Webster ]

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. Knight. [ 1913 Webster ]

Urchin fish (Zool.), a diodon. [ 1913 Webster ]

a. Rough; pricking; piercing. [ R. ] “Helping all urchin blasts.” Milton. [ 1913 Webster ]