Reniform

Reniform is a descriptive term meaning kidney-shaped. It derives from the Latin reniformis ('kidney-shaped'), formed from renes (kidney) and forma (shape). The word is used across disciplines to denote objects or outlines that resemble the shape of a kidney, typically rounded with a central indented region.

In biology and medicine, reniform is commonly used to describe leaves, seeds, or lesions that have a kidney-like outline. For example, reniform leaves are kidney-shaped with a bilobed base. In clinical descriptions it may refer to structures or lesions whose morphology is kidney-shaped, without implying function.

In geology and mineralogy, reniform describes grains or nodules whose outline is kidney-shaped; the term helps distinguish textures in rocks and ore minerals. The concept is purely descriptive and does not indicate composition.