This is the 347th most frequent Russian word.
никто
"Никто" means "nobody" or "no one."
'Никто' is used here as the subject of the sentence, carrying the meaning 'no one'. It emphasizes the absence of people attending.
Никто не пришёл на встречу.
No one came to the meeting.
'Никому' (dative form of 'никто') is used as an indirect object, signifying 'to no one', instructing not to disclose the secret.
Это секрет, никому не говори.
It's a secret, don't tell anyone.
'Никого' (genitive form of 'никто') is used as part of the preposition 'без', highlighting the absence of people in the context.