Postero

Postero is a combining form used in medical and anatomical terminology to denote a position toward the back of the body or behind a reference point. The term derives from Latin posterus, meaning following or rear, and is used to form compounds that describe relative locations.

In practice, postero- appears in terms such as posteroanterior, posterosuperior, and postero-inferior. A common example is the posteroanterior chest radiograph, in which the X-ray beam passes from the posterior to the anterior aspect. The prefix helps distinguish posterior-oriented surfaces, parts, or directions from their anterior counterparts.

In anatomy, postero- is used to describe the posterior aspect of bones, organs, and anatomical regions; it can combine with various roots to designate surfaces or directions (for example, postero-lateral aspects of the skull or spine).

Language notes: in languages such as Italian and Spanish, postero can function as an independent adjective or noun meaning the rear part or the latter; in English medical writing, however, it is mainly encountered as a combining form rather than a standalone word.