stranger
STRANGER noun
[ C ] uk/ˈstreɪndʒər/ usB1 someone you have never met before
незнакомец
I can't just walk up to a complete stranger and start speaking to them. be no stranger to sth
to have a lot of experience of something
хорошо знать что-либо, знать не понаслышке
He's no stranger to hard work himself.