To wake up early in the morning in the dead of winter with the sole intent of taking an excessively long shower. A true Sander is done when you know that everyone else is waiting and relying on a shower to get them through the day. Getting Sandered may result in a pathological phenomenon known as an "undeSANDERED" testicle when your roommates attempt to shower after you.
Hey man, make it quick. I got Sandered yesterday and my balls still haven't dropped back down.