This is the 4907th most frequent Russian word.
километр
Kilometer – a unit of length equal to 1,000 meters.
Here, 'километров' is used as the direct object in the accusative case, modified by the numeral 'ten', indicating distance traveled.
Мы прошли десять километров, чтобы добраться до деревни.
We walked ten kilometers to reach the village.
In this sentence, 'километрах' appears in the prepositional case, showing location concerning distance.
Озеро находится в двух километрах от города.
The lake is located two kilometers away from the city.
The form 'километров' is used in the genitive plural, indicating a measure or quantity associated with the distance.