To press something, especially someone’s skin, strongly between two hard things such as a finger and a thumb, usually causing pain. (Cambridge Dictionary)
To squeeze between the finger and thumb or between the jaws of an instrument. (Merriam – Webster)
Grip (something, typically a person’s flesh) tightly and sharply between finger and thumb. (Oxford Dictionaries)
If you pinch a part of someone’s body, you take a piece of their skin between your thumb and first finger and give it a short squeeze. (Collins Dictionary)
Two hands and a pinch stock image.