He squirmed in his seat when the teacher praised him in front of the class.

squirmed 是动词 squirm 的过去式，squirm 的意思是"扭动身体、局促不安地移动"，通常用来形容因为尴尬、紧张或不自在而做出的不自主的小动作。这个词常用来描述人在感到不自在时的身体反应。