posteriorly

Posteriorly is an adverb describing position toward the back or rear of a body, object, or scene relative to a specified reference point. It is the adverbial form of the adjective posterior, which derives from Latin posterior meaning “coming after,” from post meaning “after.” In anatomical usage, posteriorly indicates a direction toward the dorsal side of humans and toward the rear end in non-human vertebrates. It is commonly used in diagrams, clinical descriptions, and anatomical texts to avoid ambiguity with anteriorly (toward the front).

In humans, anterior corresponds to the ventral side and posterior to the dorsal side; in quadruped animals, posterior typically means toward the hindquarters or tail. The term is used alongside other directional terms such as superior/inferior, medial/lateral, and proximal/distal to specify location precisely. It helps describe relationships between structures when a reference point is established.

Usage notes: While standard in scientific writing, "posteriorly" may sound formal; alternatives include "toward the back" or "behind" depending on context. It is often found in phrases such as "posteriorly located" or "posteriorly to the..." and can introduce comparisons or relationships between structures. Because orientation terms can differ between species, authors often specify the reference frame, for example "posterior to the frontal bone" or "posteriorly to the heart."