When a guy shakes his head while eating a girl out. For some reason guys think that girls like this. It's really kind of annoying. And if he hasn't shaved like five minutes before it kind of hurts.

Intelligence agency term for "psychological operation". A government or corporate-sponsored operation, usually taking the form of a "terrorist attack" or "crazed gunman on a spree", with the intent of panicking the public into demanding more police and laws inhibiting freedom. Psyops are usually carried out by drugging a civilian or group of civilians with aggression-promoting drugs, psyching them up, arming them, and sending them out to commit mayhem. Government-sponsored terrorism. See also blackshirts, conspiracy

The act of shaking ones head in a manner which not only implies disbelief. But also a complete lack of surprise that the person causing the shake is a serial cause for your head to be shaken.