The Collaborative International Dictionary of English v.0.48:

Gliadin \Gli"a*din\, n. [Gr. ? glue: cf. F. gliadine.] (Chem.)
   Vegetable glue or gelatin; glutin. It is one of the
   constituents of wheat gluten, and is a tough, amorphous
   substance, which resembles animal glue or gelatin.
   [1913 Webster]