This is the 9266th most frequent Portuguese word.
casou
"Casou" means "married" (past tense of the verb "casar").
Here, 'casou' is used as a verb to indicate the act of getting married.
Ela casou com ele no último verão.
She married him last summer.
In this case, 'casou' is used metaphorically to mean 'matched' or 'fit'.
Casou bem com o trabalho que executou.
It matched well with the work he did.
Again, 'casou' is used as a verb detailing the act of getting married, indicating a past event.