Source : Webster's Revised Unabridged Dictionary (1913)

Bay tree \Bay" tree`\
   A species of laurel. ({Laurus nobilis}).

Source : WordNet®

bay tree
     n : small Mediterranean evergreen tree with small blackish
         berries and glossy aromatic leaves used for flavoring in
         cooking; also used by ancient Greeks to crown victors
         [syn: {true laurel}, {bay}, {bay laurel}, {Laurus nobilis}]