This is the 590th most frequent Portuguese word.
nossas
"Nossas" means "our" or "ours" (feminine plural).
Here, 'nossas' is used as a possessive adjective indicating that the ideas belong to the speaker and at least one other person.
Nossas ideias foram apresentadas ontem.
Our ideas were presented yesterday.
'Nossas' is used here to attribute the tasks to the speaker and their cohort, showing collective ownership.
Vamos organizar nossas tarefas antes de começarmos.
Let us organize our tasks before we start.
In this sentence, 'nossas' is specifying ownership of the chairs, emphasizing that they are the speaker's and their group's.