celled

Celled is an adjective used in biology to indicate that something is composed of cells or has cellular organization. It is applied to organisms, tissues, and structures to distinguish them from non-cellular or acellular forms. In this sense, celled contrasts with acellular, a term used for things that lack cells, such as viruses, which are traditionally described as non-cellular.

The term appears most often in descriptive or historical contexts. In contemporary scientific writing, the more common adjective is cellular. While celled can be understood as emphasizing the presence of cells, it is less frequently used in precise taxonomic or anatomical language. When used, it generally signifies that an entity has a cellular basis rather than being a non-cellular material or concept.

Celled organisms include both unicellular and multicellular life. Examples span bacteria and archaea, many protists, as well as plants, fungi, and animals. Unicellular organisms are sometimes referred to as single-celled, highlighting that their entire life cycle occurs within one cell. Multicellular organisms comprise many cells that differentiate to perform specialized functions. The distinction between celled and acellular is a fundamental axis in biology and underpins classifications of life forms and the study of cellular structure and function.

Etymology traces celled to the root cell, with the suffix -ed indicating a state or condition. The term remains a recognized but less common variant of cellular in modern usage. See also cellular, acellular.