This is the 2343rd most frequent Portuguese word.
one
"One" is not a Portuguese word; in Portuguese, it translates to "um" (masculine) or "uma" (feminine), meaning the numeral "1."
The word 'um' (one) is used as an indefinite article to refer to a single, unspecified bird.
Eu vi um pássaro voando.
I saw a bird flying.
The word 'único' (only, one) is used as an adjective to indicate exclusivity in count.
Ele é o único aluno da turma que tirou nota máxima.
He is the only student in the class who scored the highest grade.
The word 'uma' (one) is used as an indefinite article matching the feminine noun 'fatia' (slice), denoting a single portion.