infra-sónico

== Portuguese == === Adjective === infra-sónico (feminine infra-sónica, masculine plural infra-sónicos, feminine plural infra-sónicas) (European Portuguese spelling) pre-reform spelling (used until 1990) of infrassónico; still used where the agreement hasn’t come into effect and may occur as a sporadic misspelling === Further reading === “infra-sónico”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026