Lexicon

5.8, 5.9, 5.10, etc.		Pronounced “five eight, five nine, five ten, etc.,” it is the American rating system for climbs. The “five” part before the decimal dictates what category the surface is, that is to say whether it is horizontal or vertical. 1 means the ground is a horizontal hiking trail, 5 means it is a vertical face. The number after the decimal is the difficulty of the climb. 5.1 is a baby climb. Most people can do a 5.6, and that is what most carnival climbing towers are. 5.9 is considered a beginner range, and 5.10 is when more serious climbing begins. The limit of human capability is a 5.15, and only a handful of people in the world can accomplish these climbs.
Anchors		The two parallel bolts at the top of the climb which complete the route. Once a climber has reached this point, they clip into both, and rappel back down.
Belay		The action of controlling the rope from the ground. This either means feeding rope up, or taking rope in, depending on the climbing style. The person doing this action is called the belayer.
Bolts		A permanent anchor in the rock installed individually as a protection device, or with other bolts or protection devices as an anchor. The bolt is a metal shaft 1/4 inch, 3/8 inch or 5/16 inch in diameter (common sizes), driven into a hole drilled by the climber, and equipped with a hanger to attach a carabiner.
Crimper		A very small handhold that you have to crimp just the tips of your fingers on to hold onto.
Draws, or quick draws		The protection points you clip into bolts on the rock face.
Jug		Also known as "THANK GOD!' holds, it's a very large handhold where your fingers can curve down into it. They are very easy to hold, and really just wonderful.
Lead Climbing		to climb starting with the rope on the ground clipping into protection points on the way up. You literally are taking the rope up with you. Falling really stinks in this type of climbing.
Overhang		A rock face that is less than 90 degrees. Can vary from the last 10 feet of a climb, to the majority of a climb, from just barely overhung, to one where the climber is completely upside-down.
Run-out		This is when your protection, the bolts you clip into on a lead climb, is very far away from where you are. A route can be vertically run-out, where the bolt above you is very far away, or horizontally, where you climb far to the side of where your protection is and must traverse back.
Slab		Any climb that is less than vertical, especially those devoid of features requiring smearing of the feet.
Smear		Not pertaining to bagels. In climbing-ese, this is when you have no foot holds, and so you use the friction from the rubber on your shoes and the texture of the rock to push upward.
Top-rope		This is what standard climbing is, where the rope is fixed at the top. If you’ve ever tried out rock climbing for the first time, this is what you did.
Whipper		The slang for falling on a lead climb. It is called a whipper because when you are lead climbing, your protection (i.e. the point on the wall that your rope is attached to) can be up to ten feet beneath you. That mean if you were to fall, you fall that ten feet, plus the ten feet beneath that, and the little bit extra that the rope will stretch. Like this http://www.youtube.com/watch?v=vU7ywusVWv4&feature=player_detailpage#t=59s