This is the 5559th most frequent Russian word.
пополнением
"Addition" or "replenishment."
Here, 'пополнением' refers to a new member joining the family, such as a newborn baby.
Поздравляем с пополнением в семье!
Congratulations on the addition to your family!
In this sentence, 'пополнением' denotes an increase or replenishment in financial resources.
Этот месяц завершился пополнением бюджета.
This month ended with a budget increase.
Here, 'пополнением' is used to describe the action of expanding or augmenting a collection.