Flattened

Flattened is the past participle of flatten and functions as both a verb and an adjective. As a verb, it means to make something flat or to compress it. As an adjective, it describes a state or condition in which an object or structure has been made flat or reduced in height. The term is used across many fields to indicate a loss of curvature, height, depth, or structure.

In geometry and planetary science, flattening refers to the deviation of a body from a perfect sphere. It is quantified by the flattening factor f = (a − b)/a, where a is the equatorial radius and b is the polar radius. Rotating bodies like planets and stars tend to become oblate, with a flattened polar region and an equatorial bulge. The Earth is commonly modeled as an oblate spheroid due to this flattening.

In computing and data processing, flattening describes reducing a hierarchical or multi-dimensional structure to a simpler form. Examples include flattening a multi-dimensional array into a one-dimensional sequence, flattening nested data structures (such as JSON or XML) into a flat list, or flattening an image by merging layers into a single composite image. In graphic design software, “flattening” a file often refers to merging all layers into one.

In biology and anatomy, flattened describes cells or tissues that are thin and broad. For instance, squamous epithelial cells are described as flattened, and certain plant leaves or structures may appear flattened in form.

In geology and archaeology, flattening can refer to processes or results that reduce relief or shape, such as abrasion creating flatter, smoother surfaces.