Source : Webster's Revised Unabridged Dictionary (1913)

Sea hare \Sea" hare`\ (Zo["o]l.)
   Any tectibranchiate mollusk of the genus Aplysia. See
   {Aplysia}.

Hare \Hare\, n. [AS. hara; akin to D. haas, G. hase, OHG. haso,
   Dan. [ae] Sw. hare, Icel. h?ri, Skr. ?a?a. ?.]
   1. (Zo["o]l.) A rodent of the genus {Lepus}, having long hind
      legs, a short tail, and a divided upper lip. It is a timid
      animal, moves swiftly by leaps, and is remarkable for its
      fecundity.

   Note: The species of hares are numerous. The common European
         hare is {Lepustimidus}. The northern or varying hare of
         America ({L. Americanus}), and the prairie hare ({L.
         campestris}), turn white in winter. In America, the
         various species of hares are commonly called {rabbits}.

   2. (Astron.) A small constellation situated south of and
      under the foot of Orion; Lepus.

   {Hare and hounds}, a game played by men and boys, two, called
      hares, having a few minutes' start, and scattering bits of
      paper to indicate their course, being chased by the
      others, called the hounds, through a wide circuit.

   {Hare kangaroo} (Zo["o]l.)., a small Australian kangaroo
      ({Lagorchestes Leporoides}), resembling the hare in size
      and color,

   {Hare's lettuce} (Bot.), a plant of the genus {Sonchus}, or
      sow thistle; -- so called because hares are said to eat it
      when fainting with heat. --Dr. Prior.

   {Jumping hare}. (Zo["o]l.) See under {Jumping}.

   {Little chief hare}, or {Crying hare}. (Zo["o]l.) See {Chief
      hare}.

   {Sea hare}. (Zo["o]l.) See {Aplysia}.

Source : WordNet®

sea hare
     n : naked marine gastropod having a soft body with reduced
         internal shell and two pairs of ear-like tentacles [syn:
         {Aplysia punctata}]