This is the 7161st most frequent Swedish word.
rugby
A team sport played with an oval ball, involving running, passing, and tackling.
Here, 'rugby' is used as a noun referring to the sport itself in a general sense.
Vad spännande att titta på en rugby-match.
How exciting it is to watch a rugby match.
In this sentence, 'rugby' is used as a noun representing the activity of playing the sport itself.
Jag spelade rugby efter skolan igår.
I played rugby after school yesterday.
Here, 'rugby' modifies 'ball', forming a compound noun 'rugby ball' which specifies the type of ball used in rugby then describing its unique features.