grimace
definition
a facial expression that shows disgust, pain, or disapproval
example
She couldn't hide her grimace of disgust when she tasted the sour milk.
synonyms
scowlfrownwince
word origin — The word 'grimace' comes from the French word 'grimace' meaning 'a distortion of the face', which is believed to have its roots in the Middle French 'grimaçe'.