Lobster

n.
  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.
    3. Lobster caterpillar (Zoöl.),
    the caterpillar of a European bombycid moth (Stauropus fagi); -- so called from its form.
    Lobster louse (Zoöl.),
    a copepod crustacean (Nicothoë astaci) parasitic on the gills of the European lobster.