D defs.my
Entry 2 senses Webster, 1913

Lobster

/läb'-stẽr/ · Lob·ster · IPA /ˈlɑb.stɚ/
01 n. Any large macrurous crustacean used as food, esp. those of the genus Homarus; as the American lobster (Homarus Americanus), and the Europea…
  1. 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.(Zool.)
  2. 2.
    As a term of opprobrium or contempt: A gullible, awkward, bungling, or undesirable person.[Slang]
Phrases & compounds
Lobster caterpillar — the caterpillar of a European bombycid moth (Stauropus fagi); -- so called from its form.
Lobster louse — a copepod crustacean (Nicothoë astaci) parasitic on the gills of the European lobster.