To blow all the air out of your lungs possible, bend down with your back straight, making your face go towards the ground, whilst keeping your legs straight. And to then put a joint in your mouth and inhale as deep as possible, while straightening back up. Then you hold your thumb in your mouth, and blow on it as hard as you can (make sure to not release any smokes), and keep doing it until you feel like your going to pass out.

Used to describe (generally female) imagery that's suggestive, but in a PG-13 sense rather than an R or above sense.