To travel wicked fast, usually in the downhill direction. It is all about sweet flow. Some report the sensation of floating. Some experience symptoms of permagrin. Experienced pumers describe pumin' as a state of mind, absent of thought. Often they describe they find themselves pumin' without realizing it at first. It just happens.
Pronounced like the sound a 10 year old boy makes when shooting invisible lasers. "Pyume pyume!".
My buddy pumed me to the top of the mountain in her truck, then I pumed down some sweet singletrack. I was so in the zone that there was only the pume. Later on we met up for a surf and went pumin' down some tasty waves. It's more fun with fellow pumers.