Frowned, grimaced.
Some synonyms for "scowled" are frowned, glared, and scowled.
The gutsy soldier just silently grimaced.
My Grandad grimaced when he saw me kick my ball at his greenhouse.
The word grimaced is a verb. It is the past tense of grimace.
Example: Ashley grimaced when she saw her grade on the math test. Dictionary definition: A facial expression that indicates disapproval or pain.
frowned, glowered, glared, grimaced
You ask them the reason for the facial expression.
I stared into his eyes gloomily. He grimaced then struck me in the face.
The cab driver's face grimaced in repulsion to the scene of the accident.
Grimace is a noun and a verb. It just depends on how you use it. Noun form: The grimace of the refugees in the photograph reveals the pain of homelessness. Verb form: Most people grimace at the mere sound of the dentist's drill.
I grimaced upon reading the lack of grammar in this question. There was a grimace upon my face on reading this question.