When you taste something very sour and you twist your face up in an odd expression to show your displeasure, this is an example of a time when you contort your face.
Fingers contorted by arthritis.
The leaders of the movement contorted their own principles in trying to get what they wanted.
A face contorted with pain.
Origin of contort
From American Heritage Dictionary of the English Language, 5th Edition
- con- + -tort, from Middle English, from Latin contortus, past participle of contorquere, from com- + torqueō (“twist, turn”).