This is the 5118th most frequent Russian word.
называем
"Называем" means "we call" or "we name."
Here, 'называем' is used to indicate naming or designation, implying that the river is referred to by this specific name.
Мы называем эту реку Волгой.
We call this river the Volga.
In this sentence, 'называем' is used to express attributing a characteristic or title to someone.
Они называют его лучшим учеником в классе.
They call him the best student in the class.
Here, 'называют' is used in a passive-like sense to indicate how the subject is commonly referred to by people.