Act of exasperation, in modern-day slang

• Head-smacking gesture: Hyph
• Frustrated hand-to-head gesture: Hyph
• Nonverbal groan
• Alternative to a head slap
• [I'm such an idiot!]
• [I can't believe that just happened!]
• Nonverbal equivalent of "You have got to be kidding me!"

Wikipedia Word definitions in Wikipedia
A facepalm (sometimes also face-palm or face palm ) is the physical gesture of placing one's hand flat across one's face or lowering one's face into one's hand or hands, covering or closing the eyes. The gesture is often exaggerated by giving the motion ...

Wiktionary Word definitions in Wiktionary
n. A gesture of bringing one palm or both palms to the face, with various interpretations. vb. 1 To bring the palm of one’s hand to one’s face as an expression of mixed humor and disbelief or disgust or shame, for example, when one is caught off-guard with ...