Facial means relating to the face. A facial expression is the look on someone's face that shows their emotions: happiness, surprise, confusion, or anger. When you watch a friend's facial reactions during a scary movie, you're seeing how their face changes as the tension builds.

Doctors and scientists study facial features to understand genetics, identify people, or diagnose medical conditions. Facial recognition technology can identify someone by analyzing the unique characteristics of their face, like the distance between their eyes or the shape of their jawline.

The word can also be a noun, meaning a treatment where someone cleans, massages, and applies products to your face to keep skin healthy. A facial at a spa might include washing, exfoliating, and moisturizing.

You might hear the term facial hair for beards, mustaches, or whiskers that grow on someone's face. Scientists who study expressions talk about facial muscles, the small muscles that let us smile, frown, raise our eyebrows, or wrinkle our noses. Your face has over 40 muscles working together to create thousands of different expressions, and anything involving those muscles or the surface of your face can be described as facial.