This is the 936th most frequent Persian word.
رودخانه
River
Here, "رودخانه" is used as a subject of the sentence indicating a natural water body.
رودخانه در نزدیکی خانه ما جاری است.
The river flows near our house.
In this sentence, "رودخانه" is used as the object of a preposition referring to the river next to which walking is taking place.
ما در حاشیه رودخانه قدم میزنیم.
We walk along the riverbank.
In this example, "رودخانه" is part of a possessive compound emphasizing that the water originates from the river.