Ratus

Ratus is a Latin term that functions as the masculine singular past participle of the verb reor, meaning having been thought, judged, or considered. In classical Latin it appears as an adjective or participial adjective and agrees with the noun it modifies, conveying that something has been deemed or calculated. The form is commonly found in legal, philosophical, or administrative contexts, where it helps indicate a decision, assessment, or conclusion that has already taken place.

The feminine and neuter forms are rata and ratum, with corresponding plural forms used in standard 1st/2nd declension patterns. As a participial adjective, ratus can be used to describe nouns in a way that parallels English equivalents such as deemed, considered, or reckoned, and it often functions in phrases that convey a completed evaluation or resolution within Latin prose.

In modern usage, ratus is primarily encountered in linguistic or historical discussions of Latin grammar and translation. It is not a term with independent everyday meaning in English outside scholarly or ancient-text contexts. Speakers should not confuse it with similar-looking terms from other domains; for example, it is distinct from the taxonomic genus Rattus, which includes true rats. When encountered in English-language scholarship, ratus is usually part of a quotation or a discussion about Latin morphology rather than a contemporary concept.

See also: Rattus, Latin grammar, Latin participles.