This is the 463rd most frequent Finnish word.
kevään
"Kevään" means "of the spring" (possessive form of "kevät," spring).
In this sentence, "kevään" is the genitive singular form of "kevät" (spring) and is used to indicate time association.
Kevään tullessa kukat alkavat kukkia.
As spring arrives, flowers start to bloom.
Here, "kevään" describes the days belonging to the spring season, showing possession or association.
Pidän kevään lämpimistä päivistä.
I like the warm days of spring.
The genitive form "kevään" is used to specify the association of the colors with the spring season.