DISASSIMILATION
Source: 567
Dis′as‐sim′i‐la″tion (?), n. (Physics) The decomposition of complex substances, within the organism, into simpler ones suitable only for excretion, with evolution of energy, — a normal nutritional process the reverse of assimilation; downward metabolism. The breaking down of already existing chemical compounds into simpler ones, sometimes called disassimilation. Martin.