This is the 2889th most frequent Portuguese word.
fies
"Fies" is the acronym for "Fundo de Financiamento Estudantil," a Brazilian government program that provides student loans for higher education.
Here, 'fiéis' is used as an adjective meaning 'loyal', describing the students' characteristic.
Os alunos são muito fiéis ao professor.
The students are very loyal to the teacher.
In this sentence, 'FIES' refers to 'Fundo de Financiamento Estudantil', a Brazilian student loan program. It is used as a proper noun.
O contrato do FIES foi aprovado pelo governo.
The FIES contract was approved by the government.
'Fiéis' acts as an adjective meaning 'loyal', but in this case it defines adherence to principles or morals.