The Collaborative International Dictionary of English v.0.48:

Breadfruit \Bread"fruit`\, n. (Bot.)
   1. The fruit of a tree (Artocarpus incisa) found in the
      islands of the Pacific, esp. the South Sea islands. It is
      of a roundish form, from four to six or seven inches in
      diameter, and, when baked, somewhat resembles bread, and
      is eaten as food, whence the name.
      [1913 Webster]

   2. (Bot.) The tree itself, which is one of considerable size,
      with large, lobed leaves. Cloth is made from the bark, and
      the timber is used for many purposes. Called also
      breadfruit tree and bread tree.
      [1913 Webster]

WordNet (r) 3.0 (2006):

breadfruit
    n 1: native to Pacific islands and having edible fruit with a
         texture like bread [syn: breadfruit, breadfruit tree,
         Artocarpus communis, Artocarpus altilis]
    2: a large round seedless or seeded fruit with a texture like
       bread; eaten boiled or baked or roasted or ground into flour;
       the roasted seeds resemble chestnuts