The Collaborative International Dictionary of English v.0.48:

Beebread \Bee"bread`\, n.
   A brown, bitter substance found in some of the cells of
   honeycomb. It is made chiefly from the pollen of flowers,
   which is collected by bees as food for their young.
   [1913 Webster]

WordNet (r) 3.0 (2006):

beebread
    n 1: a mixture of nectar and pollen prepared by worker bees and
         fed to larvae [syn: beebread, ambrosia]