Source : Webster's Revised Unabridged Dictionary (1913)

Peptone \Pep"tone\, n. [Gr. ? cooked.] (Physiol. Chem.)
   (a) The soluble and diffusible substance or substances into
       which albuminous portions of the food are transformed by
       the action of the gastric and pancreatic juices. Peptones
       are also formed from albuminous matter by the action of
       boiling water and boiling dilute acids.
   (b) Collectively, in a broader sense, all the products
       resulting from the solution of albuminous matter in
       either gastric or pancreatic juice. In this case,
       however, intermediate products (albumose bodies), such as
       antialbumose, hemialbumose, etc., are mixed with the true
       peptones. Also termed albuminose.

Source : WordNet®

peptone
     n : any of various water-soluble compounds that form by
         hydrolysis in the digestion of proteins to amino acids