communis

Communis is a Latin adjective meaning common or shared by all. It appears in Latin phrases across legal, philosophical, and scholarly contexts to denote universality, generality, or collective ownership. In Roman law, res communis referred to things that belong to the public or to all members of a community and cannot be owned privately, such as air or navigable waters. By contrast, res privata describes private property. In other domains, communis appears in phrases such as opinio communis (common opinion) and ratione communis (the common basis of judgment), indicating collective or general characteristics.

In biology and botany, communis is used as a Latin epithet in species names to indicate that a species is common or widespread in a region or habitat; many genera feature such epithets, though usage varies by author and era.

In modern usage, the term persists in the concept of the “commons”—resources that are collectively owned or governed by a community or society. The word underpins discussions of public goods, shared resources, and communal life, and it remains a productive root in law, philosophy, and ecology. The form communis serves as a reminder of the Latin roots of many English terms that describe shared or public aspects of society.