This is the 4315th most frequent Russian word.
банках
"Банках" means "jars" or "banks" (plural, prepositional case).
The word 'банках' refers to financial institutions in the form of plural dative or genitive case (depending on the sentence structure).
Он работает в банках мира.
He works in the banks of the world.
The word 'банках' refers to glass jars used for storage, employing the plural prepositional case.
Они нашли старые монеты в стеклянных банках.
They found old coins in glass jars.
The word 'банках' again relates to financial institutions, used in the plural prepositional case.