stranger (n)

My mother always warned me not to talk to strangers.
I'd never met anyone at the party before - they were complete strangers.
It's essential to teach children not to talk to strangers and prioritize safety.
The city streets were filled with strangers going about their daily routines.
Striking up a conversation with a stranger can lead to unexpected connections.
The protagonist encountered a mysterious stranger who played a pivotal role in the story.