This is the 2086th most frequent Swedish word.
bros
Cartilage.
Here, 'bron' (the bridge) is a noun, referring to a physical structure that spans across water or another obstacle.
Den gamla bron över floden var byggd av sten.
The old bridge over the river was made of stone.
In this instance, 'bron' is used as a definite noun, indicating a specific bridge being referenced.
Jag har alltid velat bo vid en plats där man kan se bron från fönstret.
I have always wanted to live in a place where one can see the bridge from the window.
'Broar' here is the plural indefinite form, denoting more than one bridge without specifying which ones.