This is the 1544th most frequent Russian word.
причины
Reasons.
The word 'причина' is used as a noun here to denote the main cause or reason for an event.
Основная причина этого события была недостаточная подготовка.
The main reason for this event was insufficient preparation.
The word 'причины' is used in plural form here to signify multiple reasons or causes being investigated.
Мы ищем причины его неожиданного поведения.
We are looking for the reasons for his unexpected behavior.
The word 'причина' implies the underlying factor or explanation for an achievement in this context.