This is the 2578th most frequent Portuguese word.
fixa
"Fixa" means "permanent," "fixed," or "stationary" in English.
In this sentence, "fixa" is used as an adjective to mean 'fixed', describing the noun 'ideia'.
Ela tem uma ideia fixa sobre o projeto.
She has a fixed idea about the project.
Here, "fixa" is a verb in the present tense, third person singular, meaning 'to fix' or 'to attach'.
Ele fixa o quadro na parede.
He fixes the painting on the wall.
In this sentence, "fixa" again is an adjective modifying 'lembrança', meaning 'fixed' or 'permanent'.