late 14c., from Old French digestion (13c.), from Latin digestionem (nominative digestio), noun of action from past participle stem of digerere (see digest (n.)).
digestion di·ges·tion (dī-jěs'chən, dĭ-)
n.
The process by which food is converted into substances that can be absorbed and assimilated by the body, especially that accomplished in the alimentary canal by the mechanical and enzymatic breakdown of foods into simpler chemical compounds.
The breaking down of food, which is made up of complex organic molecules, into smaller molecules that the body can absorb and use for maintenance and growth.