face palm

/F EY1 S P AA0 M/
noun
  1. 1

    A gesture of bringing one or both palms to the face, with various interpretations.

verb
  1. 1

    To bring the palm of oneโ€™s hand to oneโ€™s face as an expression of mixed humor and disbelief, disgust or shame; for example, when one is caught off-guard with a particularly bad pun.

  2. 2

    To bring oneโ€™s face down to oneโ€™s cupped hand or hands.

Source: https://en.wiktionary.org/wiki/face%20palm, https://en.wiktionary.org/wiki/facepalm