\Por"cu*pine\, n. [OE. porkepyn, porpentine, OF.
porc-espi, F. porc-['e]pic (cf. It. porco spino, porco
spinoso, Sp. puerco espino, puerco espin, fr. L. porcus swine
+ spina thorn, spine). The last part of the French word is
perhaps a corruption from the It. or Sp.; cf. F. ['e]pi ear,
a spike of grain, L. spica. See {Pork}, {Spike} a large nail,
{Spine}.]
1. (Zo["o]l.) Any Old Word rodent of the genus {Hystrix},
   having the back covered with long, sharp, erectile spines
   or quills, sometimes a foot long. The common species of
   Europe and Asia ({Hystrix cristata}) is the best known.
2. (Zo["o]l.) Any species of {Erethizon} and related genera,
   native of America. They are related to the true
   porcupines, but have shorter spines, and are arboreal in
   their habits. The Canada porcupine ({Erethizon dorsatus})
   is a well known species.
{Porcupine ant-eater} (Zo["o]l.), the echidna.
{Porcupine crab} (Zo["o]l.), a large spiny Japanese crab
   ({Acantholithodes hystrix}).
{Porcupine disease} (Med.). See {Ichthyosis}.
{Porcupine fish} (Zo["o]l.), any plectognath fish having the
   body covered with spines which become erect when the body
   is inflated. See {Diodon}, and {Globefish}.
{Porcupine grass} (Bot.), a grass ({Stipa spartea}) with
   grains bearing a stout twisted awn, which, by coiling and
   uncoiling through changes in moisture, propels the
   sharp-pointed and barbellate grain into the wool and flesh
   of sheep. It is found from Illinois westward. See
   Illustration in Appendix.
{Porcupine wood} (Bot.), the hard outer wood of the cocoa
   palm; -- so called because, when cut horizontally, the
   markings of the wood resemble the quills of a porcupine.