Source : Webster's Revised Unabridged Dictionary (1913)

Gluten \Glu"ten\, n. [L., glue: cf. F. gluten. See {Glue}.]
   (Chem.)
   The viscid, tenacious substance which gives adhesiveness to
   dough.

   Note: Gluten is a complex and variable mixture of glutin or
         gliadin, vegetable fibrin, vegetable casein, oily
         material, etc., and ia a very nutritious element of
         food. It may be separated from the flour of grain by
         subjecting this to a current of water, the starch and
         other soluble matters being thus washed out.

   {Gluten bread}, bread containing a large proportion of
      gluten; -- used in cases of diabetes.

   {Gluten casein} (Chem.), a vegetable proteid found in the
      seeds of grasses, and extracted as a dark, amorphous,
      earthy mass.

   {Gluten fibrin} (Chem.), a vegetable proteid found in the
      cereal grains, and extracted as an amorphous, brownish
      yellow substance.

Source : WordNet®

gluten
     n : a protein substance that remains when starch is removed from
         cereal grains; gives cohesiveness to dough