Biology. A connected and organized arrangement of physical components forming a living organism or part of one.

concrete. An organized structure; a body; an organism. Obsolete.

Zoology. Each of the distinct beings which make up a colonial organism, and which typically have different forms and functions. Cf. person, n. 9.

Chiefly Biology. A group of organisms or (formerly) mineral substances, or types of these, exhibiting similar characteristics or a constant…

An individual animal, plant, or single-celled life form. Also: the material structure of such an individual; an instance of this.