Alterno

Alterno is a term used in several Romance languages, primarily as an adjective meaning alternating or occurring in turns. In Italian and Spanish the masculine form is alterno, with gendered forms used to agree with nouns (for example, alterna for feminine in Italian and alterna/alternos in Spanish). The word derives from Latin alternus, from alter, meaning “the other” or “one of two,” reflecting the idea of turn-taking or succession.

In everyday and technical usage, alterno describes patterns, cycles, or sequences that alternate or switch between states. In Italian, common phrases include periodi alterni or sequenze alterne; in Spanish, periodos alternos or secuencias alternas. The term appears across disciplines such as mathematics, physics, biology, and linguistics to describe phenomena of alternation, such as alternating phases, alternating patterns in data, or alternation in phonology.

As a standalone noun, alterno is rare; it generally appears as part of compound terms or in adjectival phrases rather than as a proper name. There are no widely recognized places or organizations simply named Alterno in standard reference works.

See also: alternation, alternate, alternating current.