This is the 158th most frequent Portuguese word.
nossa
"Our" or an exclamation meaning "Wow" / "Oh my."
'Nossa' here is also a possessive pronoun referring to the shared ownership of the house by the speaker and others.
Alugamos a nossa casa na praia para o verão.
We rented our house at the beach for the summer.
'Nossa' in this sentence is an interjection expressing surprise or admiration.
Nossa, como o céu está bonito hoje!
Wow, the sky looks beautiful today!
'Nossa' in this sentence is a possessive pronoun indicating that the team belongs to 'us' (first person plural).