The noun 陌生人 (mòshēngrén) means "stranger" or "someone unfamiliar." It is composed of 陌生 (unfamiliar) and 人 (person). For example, 这个陌生人穿着 means "this stranger was wearing…"
妈妈说过不要随便跟陌生人说话。
Māma shuō guò bú yào suíbiàn gēn mòshēngrén shuōhuà.
Mom said not to casually talk to strangers.
一个陌生人突然在街上叫住了我。
Yí gè mòshēngrén tūrán zài jiē shàng jiào zhù le wǒ.
A stranger suddenly stopped me on the street.
她对陌生人总是很警惕,从来不轻易相信别人。
Tā duì mòshēngrén zǒngshì hěn jǐngtì, cónglái bù qīngyì xiāngxìn biérén.
She is always very wary of strangers and never easily trusts others.