This is the 3335th most frequent Russian word.
плакать
To cry.
The word 'плакать' is used here in its literal meaning, denoting the act of shedding tears.
Я начал плакать, когда услышал эту песню.
I started to cry when I heard this song.
'Плакать' expresses the general action of crying, emphasizing its emotional and therapeutic aspects.
Иногда полезно плакать, чтобы понять свои эмоции.
Sometimes it's useful to cry to understand your emotions.
Here, 'плакать' describes crying as a result of positive emotions, joy in this case.