(biology) Any organism (e.g. the fruit fly) that has been extensively studied as an example of many others, and from which general principles may be established

plural of model organism

plural of organic law

plural of organ of state

Any of the three primary divisions of a state’s sovereignty (namely, the executive, the legislature, or the judiciary); the powers of each having been divided and balanced in accordance with the political principle of the separation of powers.

(anatomy) An organ, such as the heart or colon, that is entirely within the confines of the body.

Alternative spelling of microorganism

plural of micro-organism

plural of umbrella organization

An organization that coordinates the activities of a number of member organisations to promote a common goal.