• (n.) Imperfect digestion of the several leading constituents of the food. • (n.) An imperfect elaboration by the tissues of the materials brought to them by the blood.
(mal″ә-sim″ĭ-la´shәn) imperfect, faulty, or disordered assimilation. the inability of the gastrointestinal tract to take up one or more ingested nutrients, whether due to faulty digestion (maldigestion) or to impaired intestinal mucosal transport (malabsorption).
Mal`as·sim`i·la'tion noun [ Mal- + assimilation .] (Physiol.) (a) Imperfect digestion of the several leading constituents of the food. (b) An imperfect elaboration by the tissues of the materials brought to them by the blood. 
Type: Term Pronunciation: mal′ă-sim′i-lā′shŭn Definitions: 1. Rarely used term for incomplete or faulty assimilation; malabsorption.
Defective transport of one or more nutrients from the intestinal contents across the intestinal wall.
malassimilation Imperfect assimilation; especially, in pathology, imperfect absorption of nutriments into the system.