What term is used to describe the movement of substances out of a cell?

The term that describes the movement of substances out of a cell is exocytosis. This process involves the fusion of vesicles containing the substances with the cell membrane, allowing their contents to be released into the extracellular space. Exocytosis is crucial for various cellular functions, including the secretion of hormones, neurotransmitters, and other important molecules.

In contrast, endocytosis refers to the process of taking substances into the cell, while transcytosis involves the transport of materials across the interior of a cell, typically from one side to the other. Phagocytosis, on the other hand, is a specific form of endocytosis where the cell engulfs large particles or cells. Thus, exocytosis is specifically related to the expulsion of substances, making it the correct choice for describing the movement of materials out of the cell.