1. The act or process of assimilating or bringing to a resemblance, likeness, or identity; also, the state of being so assimilated; as, the assimilation of one sound to another. To aspire to an assimilation with God. Dr. H. More. The assimilation of gases and vapors. Sir J. Herschel. 2. (Physiol.) The conversion of nutriment into the fluid or solid substance of the body, b...