Assimilation, from Latin assimilatio meaning "to render similar", is used to describe various phenomena:

• The process of assimilating new ideas into a schema (cognitive structure). See schema (psychology). In the theories of Jean Piaget, the application of a general schema to a particular instance).
• In psychoanalysis, a mutual penetration of conscious and unconscious contents.
• A linguistic process by which a sound becomes similar to an adjacent sound. See Assimilation (linguistics).
• In linguistics assimilation may also refer to the process of integrating a loanword, and if needed adapt it, into the system of the receiving language.
• The conversion of nutrient into the fluid or solid substance of the body, by the processes of digestion and absorption. See Assimilation (biology).
• The ability of water to purify itself of pollutants.
• The process whereby a minority group gradually adopts the customs and attitudes of the prevailing culture. See Assimilation (sociology).
• In economy, the absorption of a new issue by the public after all shares have been sold by the underwriting group.
• In computer science, the modification of anti-virus software to detect a new virus.
• In typesetting, the symmetry property possessed in varying degrees by a typeface that creates mirror relationships and other similarities of form between letters
• Process used by the fictional Borg race to integrate a being into the collective structure. See Assimilation (Star Trek).