What do you call an organism that consists of many cells?

An organism that consists of many cells is referred to as multicellular. This term indicates that the organism is made up of multiple cells that work together to perform various functions. Multicellular organisms can exhibit a high level of complexity and specialization, where different types of cells perform specific roles, contributing to the overall health and functionality of the organism.

In contrast, unicellular organisms are made up of a single cell, and they carry out all life processes within that one cell. Microscopic and macroscopic terms refer to the size of organisms rather than the number of cells they contain; microscopic organisms are typically too small to be seen without a microscope, while macroscopic organisms are large enough to be seen with the naked eye, which may include both unicellular and multicellular organisms. Thus, the distinction of being multicellular specifically highlights the organism's cellular structure and organization.