This is the 494th most frequent Croatian word.
nogomet
"Nogomet" means "football" or "soccer" in English.
In this sentence, 'nogomet' is used as a noun to indicate the sport of football in a general context.
Volim gledati nogomet na televiziji.
I love watching football on television.
Here, 'nogomet' is again used as a noun, now indicating an activity performed—playing the sport.
Prošli vikend smo igrali nogomet u parku.
Last weekend, we played football in the park.
In this instance, 'nogometna' is an adjective derived from 'nogomet', used to describe a ball related to football.