Meaning

• A mischievous child.

• A street urchin, a child who lives, or spends most of their time, in the streets.

• A sea urchin.

• 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 neutron-generating device that triggered the nuclear detonation of the earliest plutonium atomic bombs.

• A hedgehog.

• A mischievous elf supposed sometimes to take the form of a hedgehog.