The Collaborative International Dictionary of English v.0.48:

Bay \Bay\, n. [F. baie a berry, the fruit of the laurel and
   other trees, fr. L. baca, bacca, a small round fruit, a
   berry, akin to Lith. bapka laurel berry.]
   1. A berry, particularly of the laurel. [Obs.]
      [1913 Webster]

   2. The laurel tree (Laurus nobilis). Hence, in the plural,
      an honorary garland or crown bestowed as a prize for
      victory or excellence, anciently made or consisting of
      branches of the laurel.
      [1913 Webster]

            The patriot's honors and the poet's bays.
                                                  --Trumbull.
      [1913 Webster]

   3. A tract covered with bay trees. [Local, U. S.]
      [1913 Webster]

   Bay leaf, the leaf of the bay tree (Laurus nobilis). It
      has a fragrant odor and an aromatic taste, and is used for
      flavoring in food.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bay leaf \Bay" leaf`\
   See under 3d Bay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bay leaf
    n 1: dried leaf of the bay laurel