This is the 7559th most frequent Portuguese word.
oito
Eight.
In this usage, 'oito' specifies a duration of time measured in days.
Ele demorou oito dias para chegar.
It took him eight days to arrive.
In this sentence, 'oito' is used to denote a specific time of day.
Eu acordei às oito da manhã.
I woke up at eight in the morning.
Here, 'oito' is used as a cardinal number to indicate a quantity.