faceplam
When you try to slap your face like a idiot but miss completely and hit the desk instead, making your brain scream.
'I can't believe he failed the test again!', faceplam, desk hit, brain scream.
'She said the sky is purple? I faceplammed and knocked over my coffee.'
'He just told me the same joke for the 10th time. I faceplammed and broke my phone.'