What is "limnoria lignorum"

Gribble \Grib"ble\, n. [Cf. Prov. E. grib to bite.] (Zo["o]l.) A small marine isopod crustacean ( Limnoria lignorum or Limnoria terebrans), which burrows into and rapidly destroys submerged timber, such as the piles of wharves, both in Europe and America.

Limnoria lignorum, commonly known as the gribble, is a species of isopod in the family Limnoriidae. It is found in shallow water in the North Atlantic and North Pacific Ocean where it tunnels into wood and attacks and destroys submerged wooden structures.