This is the 8180th most frequent Portuguese word.
susanna
"Susanna" is a proper noun, typically used as a given name, equivalent to "Susannah" or "Suzanne" in English.
Here 'Susanna' is used as a proper noun to refer to a person, likely the subject of the sentence.
Susanna comprou um novo livro para estudar.
Susanna bought a new book to study.
In this case, 'Susanna' identifies the name of the person met, emphasizing the identification of this individual.
Eu conheci uma pessoa chamada Susanna na biblioteca ontem.
I met a person named Susanna at the library yesterday.
Here, 'Susanna' is discussed generally as a name with cultural or historical significance, used as a concept or category.