aeternus

Aeternus is a Latin adjective meaning "eternal" or "everlasting." In classical Latin, it is used to qualify nouns and appears in religious, philosophical, and literary contexts. The masculine form is aeternus; the feminine form is aeterna; the neuter form is aeternum. As a second-declension adjective, it follows the standard inflection patterns of adjectives of that class.

The word derives from the Latin root associated with life and age, often linked with the noun aevum ("age, lifetime"), and is cognate with terms in other Romance languages that express timelessness. The common phrase in aeternum conveys the sense of lasting without end, or for all time.

In modern usage, aeternus survives chiefly in historical texts, mottoes, liturgical language, and as a stylistic device in fiction, branding, and fantasy notation, where it is used to evoke permanence, immortality, or mythic timelessness. It is sometimes adopted as a proper name or title in music, games, and literature to convey an aura of endurance or eternity.