The Collaborative International Dictionary
Urchin \Ur"chin\ ([^u]"ch[i^]n), n. [OE. urchon, irchon, a hedgehog, OF. ire[,c]on, eri[,c]on, heri[,c]on, herichon, F. h['e]risson, a derivative fr. L. ericius, from er a hedgehog, for her; akin to Gr. chh`r. Cf. Herisson.]
(Zo["o]l.) A hedgehog.
(Zo["o]l.) A sea urchin. See Sea urchin.
A mischievous elf supposed sometimes to take the form a hedgehog. ``We 'll dress [them] like urchins, ouphes, and fairies.''
--Shak.-
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. -
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.Urchin fish (Zo["o]l.), a diodon.
Wiktionary
n. A porcupine fish.