discoidal

Discoidal is an adjective describing something that is shaped like a disk: flat, circular, and typically compact. The form is indicated by the Latin root discoid- meaning disk-like, with the usual English suffix -al.

In archaeology and lithic technology, discoidal refers to disc-shaped artifacts or to a disc-shaped reduction method. A discoidal core, for example, is roughly circular in plan and is reduced by flaking around its circumference to yield broad flakes, creating a flat, disk-like core. Discoidal flakes are also described as having a disc-like silhouette. The term is used across various regions and time periods, and its precise characteristics can vary by archaeologist and culture.

In biology and paleontology, discoidal describes organisms, shells, plates, or fossils that have disk-like outlines. It is a descriptive term rather than a taxonomic group. In geology, discoidal fossils or calcite discs may be used to describe disc-shaped mineral or fossil specimens, including certain marine invertebrates or fossil remains.

Because discoidal simply denotes shape, the term appears in other contexts such as medicine or botany to describe flat, circular structures. The common thread across uses is a reference to a circular, flat geometry rather than to a specific lineage or functional category.