Exocytosis is a biological process that involves the release of materials from a cell. Synonyms for exocytosis include secretion, expulsion, efflux, egestion, and excretion. Secretion refers to the process of releasing substances produced by the cell, while expulsion is the forceful release of waste products or unwanted substances. Efflux is the movement of materials out of the cell, while egestion specifically refers to the expulsion of undigested food from the body. Excretion is the elimination of waste products from the body, often via urine or feces. All of these words describe the process of exocytosis in different contexts and with different nuances.