This is the 448th most frequent Catalan word.
anterior
Previous; earlier; prior.
In this sentence, 'anterior' is used as an adjective to describe the noun 'dia,' indicating something that occurred before or previously.
El dia anterior, vam visitar el museu.
The previous day, we visited the museum.
Here, 'anterior' is an adjective modifying 'pàgina,' denoting the page that comes earlier in sequence within the book.
En la pàgina anterior del llibre, hi ha la resposta.
On the previous page of the book, there is the answer.
In this example, 'anterior' is used as a substantive adjective, referring to something mentioned before, specifically the previous error.