When the only person in an audience of many foolishly provides a completely unnecessary clap during the middle of a speech, show, gala, event, etc. This is caused due to the person anticipating an audience applause way too early.
The act of idiocy is followed by (a) a surge of heat rising up the spine of the tard which typically leads to complete embarrassment or (b) the unexpected pause by the speech giver and the awkward rise of a half-assed audience applause.
Opposite of the infamous afterclap
"The fag over there preclapped but the man wasn't even done talking. Just keep going Mr. Obama."