This is the 2147th most frequent Russian word.
банку
"Банку" is the accusative or dative form of "банка," meaning "jar" or "can."
Here, "банку" refers to a jar or a container used for holding items such as liquids or preserved foods.
Я положил деньги в банку.
I put the money in the jar.
In this instance, "банку" refers to a financial institution where monetary transactions occur.
Я открыл счет в банку.
I opened an account at the bank.
Here, "банку" is used to denote a can, commonly a cylindrical metal container used for storing food or beverages.