The Collaborative International Dictionary of English v.0.48:

Fig \Fig\ (f[i^]g), n. [F. figue the fruit of the tree, Pr.
   figa, fr. L. ficus fig tree, fig. Cf. Fico.]
   1. (Bot.) A small fruit tree (Ficus Carica) with large
      leaves, known from the remotest antiquity. It was probably
      native from Syria westward to the Canary Islands.
      [1913 Webster]

   2. The fruit of a fig tree, which is of round or oblong
      shape, and of various colors.
      [1913 Webster]

   Note: The fruit of a fig tree is really the hollow end of a
         stem, and bears numerous achenia inside the cavity.
         Many species have little, hard, inedible figs, and in
         only a few does the fruit become soft and pulpy. The
         fruit of the cultivated varieties is much prized in its
         fresh state, and also when dried or preserved. See
         Caprification.
         [1913 Webster]

   3. A small piece of tobacco. [U.S.]
      [1913 Webster]

   4. The value of a fig, practically nothing; a fico; -- used
      in scorn or contempt. "A fig for Peter." --Shak.
      [1913 Webster]

   Cochineal fig. See Conchineal fig.

   Fig dust, a preparation of fine oatmeal for feeding caged
      birds.

   Fig faun, one of a class of rural deities or monsters
      supposed to live on figs. "Therefore shall dragons dwell
      there with the fig fauns." --Jer. i. 39. (Douay version).

   Fig gnat (Zool.), a small fly said to be injurious to figs.


   Fig leaf, the leaf tree; hence, in allusion to the first
      clothing of Adam and Eve (Genesis iii.7), a covering for a
      thing that ought to be concealed; esp., an inadequate
      covering; a symbol for affected modesty.

   Fig marigold (Bot.), the name of several plants of the
      genus Mesembryanthemum, some of which are prized for the
      brilliancy and beauty of their flowers.

   Fig tree (Bot.), any tree of the genus Ficus, but
      especially F. Carica which produces the fig of commerce.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

fig leaf \fig leaf\
   1. The leaf from a fig tree.
      [PJC]

   2. An ornamental design shaped like the leaf of a fig tree,
      used in architecture; also, a design shaped like a fig
      leaf to cover genitalia in sculpture or paintings -- in
      reference to the biblical story in Genesis of Adam and
      Eve, who covered their privates with fig leaves.
      [PJC]

   3. Hence: [figurative] Anything used to conceal what is
      considered embarrassing or indecent. See sense 2.
      [PJC]

WordNet (r) 3.0 (2006):

fig leaf
    n 1: a leaf from a fig tree
    2: a covering consisting of anything intended to conceal
       something regarded as shameful