This is the 1852nd most frequent Swedish word.
jämna
"Jämna" means "to level," "to even out," or "to smooth."
In this sentence, 'jämn' describes the smoothness or evenness of the road.
Vägen är helt jämn efter renoveringen.
The road is completely even after the renovation.
Here, 'jämnar' is used as a verb in the present tense, meaning 'to level' or 'to even out'.
De jämnar ut marken för att bygga huset.
They are leveling the ground to build the house.
In this context, 'jämn' is used figuratively to mean 'steady' or 'consistent'.