Definition of urchin

• n. - A hedgehog.
• n. - A sea urchin. See Sea urchin.
• n. - A mischievous elf supposed sometimes to take the form a hedgehog.
• n. - A pert or roguish child; -- now commonly used only of a boy.
• n. - 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.
• a. - Rough; pricking; piercing.