What is "lobster louse"

Lobster \Lob"ster\, n. [AS. loppestre, lopystre prob., corrupted fr. L. locusta a marine shellfish, a kind of lobster, a locust. Cf. Locust.] (Zo["o]l.)

1. Any large macrurous crustacean used as food, esp. those of the genus Homarus; as the American lobster ( Homarus Americanus), and the European lobster ( Homarus vulgaris). The Norwegian lobster ( Nephrops Norvegicus) is similar in form. All these have a pair of large unequal claws. The spiny lobsters of more southern waters, belonging to Palinurus, Panulirus, and allied genera, have no large claws. The fresh-water crayfishes are sometimes called lobsters.

2. As a term of opprobrium or contempt: A gullible, awkward, bungling, or undesirable person. [Slang]

   Lobster caterpillar (Zo["o]l.), the caterpillar of a European bombycid moth ( Stauropus fagi); -- so called from its form.

   Lobster louse (Zo["o]l.), a copepod crustacean ( Nicotho["e] astaci) parasitic on the gills of the European lobster.