This is the 5002nd most frequent Swedish word.
bundesligas
"Bundesligas" is not a Swedish word; it refers to Germany's football leagues, specifically the Bundesliga.
Here, 'bundesligas' is used possessively, referring to the season belonging to the Bundesliga league.
Mitt favoritfotbollslag deltar i bundesligas säsong.
My favorite football team participates in the Bundesliga's season.
In this context, 'bundesligas' is used adjectivally, describing the type of match (a Bundesliga match).
Jag såg ett intressant bundesligas spel på TV igår.
I watched an interesting Bundesliga match on TV yesterday.
Here, 'bundesligas' is again possessive, referring to the players who belong to the Bundesliga league.