This is the 11646th most frequent Portuguese word.
periódico
"Periódico" in Portuguese means "periodical" or "magazine/newspaper issued regularly."
In this context, 'periódico' is used as a noun meaning 'journal' or 'publication' that is issued periodically.
Eu leio um periódico sobre ciência todas as semanas.
I read a journal about science every week.
Here, 'periódico' functions as an adjective meaning 'occurring at regular intervals' or 'repeated over time.'
Ele faz visitas periódicas ao médico para check-ups.
He makes periodic visits to the doctor for check-ups.
In this sentence, 'periódico' describes 'motion' as regular and recurring, pertaining to cycles or oscillations.