This is the 962nd most frequent Portuguese word.
bruna
"Bruna" is a feminine given name in Portuguese, derived from the word "bruno," meaning "brown" or "dark."
Here, 'Bruna' is used as a proper noun, the name of a person.
Bruna está feliz hoje.
Bruna is happy today.
Here, 'bruna' is used poetically as a noun referring to the dusk or twilight.
Ele chamou a bruna que cobria o horizonte ao entardecer.
He mentioned the dusk that covered the horizon at sunset.
In this case, 'bruna' is used as an adjective meaning 'dark' or 'gloomy' referring to the hue of the sky.