面孔 miànkǒng face

How to remember 面孔: 面 face + 孔 opening = face.

Characters

A face - often with a connotation of the look/type it presents - 陌生的面孔 (mòshēng de miànkǒng) an unfamiliar face; 一副冷面孔 a cold face.
Slightly more literary/written than 脸 (liǎn); good for 'faces in a crowd' or types of person (新面孔 a newcomer).
Figurative: 换了一副面孔 (to show a different face/attitude). Contrast everyday 脸 for the physical face.