The Collaborative International Dictionary of English v.0.48:

Nutmeg \Nut"meg\, n. [OE. notemuge; note nut + OF. muge musk, of
   the same origin as E. musk; cf. OF. noix muguette nutmeg, F.
   noix muscade. See Nut, and Musk.] (Bot.)
   The kernel of the fruit of the nutmeg tree (Myristica
   fragrans), a native of the Molucca Islands, but cultivated
   elsewhere in the tropics.
   [1913 Webster]

   Note: This fruit is a nearly spherical drupe, of the size of
         a pear, of a yellowish color without and almost white
         within. This opens into two nearly equal longitudinal
         valves, inclosing the nut surrounded by its aril, which
         is mace. The nutmeg is an aromatic, very grateful to
         the taste and smell, and much used in cookery. Other
         species of Myristica yield nutmegs of inferior
         quality.
         [1913 Webster]

   American nutmeg, Calabash nutmeg, or Jamaica nutmeg,
      the fruit of a tropical shrub (Monodora Myristica). It
      is about the size of an orange, and contains many aromatic
      seeds imbedded in pulp.

   Brazilian nutmeg, the fruit of a lauraceous tree,
      Cryptocarya moschata.

   California nutmeg, a tree of the Yew family (Torreya
      Californica), growing in the Western United States, and
      having a seed which resembles a nutmeg in appearance, but
      is strongly impregnated with turpentine.

   Clove nutmeg, the Ravensara aromatica, a lauraceous tree
      of Madagascar. The foliage is used as a spice, but the
      seed is acrid and caustic.

   Jamaica nutmeg. See American nutmeg (above).

   Nutmeg bird (Zool.), an Indian finch (Munia punctularia).


   Nutmeg butter, a solid oil extracted from the nutmeg by
      expression.

   Nutmeg flower (Bot.), a ranunculaceous herb (Nigella
      sativa) with small black aromatic seeds, which are used
      medicinally and for excluding moths from furs and
      clothing.

   Nutmeg liver (Med.), a name applied to the liver, when, as
      the result of heart or lung disease, it undergoes
      congestion and pigmentation about the central veins of its
      lobules, giving it an appearance resembling that of a
      nutmeg.

   Nutmeg melon (Bot.), a small variety of muskmelon of a rich
      flavor.

   Nutmeg pigeon (Zool.), any one of several species of
      pigeons of the genus Myristicivora, native of the East
      Indies and Australia. The color is usually white, or
      cream-white, with black on the wings and tail.

   Nutmeg wood (Bot.), the wood of the Palmyra palm.

   Peruvian nutmeg, the aromatic seed of a South American tree
      (Laurelia sempervirens).

   Plume nutmeg (Bot.), a spicy tree of Australia
      (Atherosperma moschata).
      [1913 Webster]