Someone who is two-faced is not sincere. They say unpleasant things about you or other people while seeming to be pleasant when they are with you.

For example:

I discovered he was a two-faced friend who was just using me to advance his career.

She always compliments my ideas but then tells everyone else they’re terrible. She is indeed two-faced. Be careful. Don’t trust her.

Since celestial twins symbolize the sign, Gemini tends to be unfairly stereotyped as two-faced or manipulative.—Katie Mannion, Peoplemag, 19 May 2024.

Tradução: hipócrita, falso, duas caras.