assimilation [L, assimulare, to make alike] , 1. the process of incorporating nutritive material into living tissue, occurring after digestion and absorption or simultaneous with absorption. 2. (in psychology) the incorporation of new experiences into a person’s pattern of consciousness. Compare apperception. 3. (in sociology and anthropology) the process in which a person or a group of people of a different ethnic background becomes absorbed into a new culture. −assimilate, v.