This is the 3790th most frequent Portuguese word.
bruno
"Bruno" is a male given name in Portuguese.
Here, 'Bruno' is used as a proper noun, referring to a person's name.
O Bruno chegou cedo na festa.
Bruno arrived early at the party.
In this sentence, 'bruno' is an adjective describing the color tone of something, specifically brownish.
O cavalo tinha um tom bruno em sua pelagem.
The horse had a brownish tone in its coat.
Here, 'bruno' is part of a specific term ('Bruno effect'), likely related to a scientific concept or theory.