This is the 8457th most frequent Russian word.
начался
"Начался" means "began" or "started."
The word 'начался' is used in the past tense to indicate the commencement of an event, specifically highlighting the time when it started.
Урок начался в восемь утра.
The lesson started at eight in the morning.
Here, 'начался' expresses the beginning of a natural occurrence (the rain starting) in the past, with emphasis on its suddenness.
Дождь начался неожиданно.
The rain started unexpectedly.
In this sentence, 'начался' is employed to describe the initiation of a festive event, specifying what marked its start.