Smearing

Daisy chain: A special purpose type of sling with multiple sewn, or tied, loops. It is significantly weaker than a normal sling.
Dead Ball: Type of High Ball boulder, where one can possibly die when falling from above.
Dead hang: To hang limp, such that weight is held by ligament tension rather than muscles.
Deadman anchor: An object buried into snow to serve as an anchor for an attached rope. One common type of such an anchor is the snow fluke.
Deadpoint: A dynamic climbing technique in which the hold is grabbed at the apex of upward motion. This technique places minimal strain on both the hold and the arms.
Deck

The ground.
To hit the ground, usually the outcome of a fall.

Deep Water Soloing: Free climbing an area that overhangs a deep enough body of water to allow for a safe fall.
Descender: A device for controlled descent on a rope. Also called a rappel device. Many belay devices may be used as descenders, including ATCs, figure eights, or even carabiners. See rappel.
Dexamethasone: A pharmaceutical drug used in the treatment of high altitude cerebral edema as well as high altitude pulmonary edema. It is commonly carried on mountain climbing expeditions to help climbers deal with altitude sickness. Also known as "dex".
Dialled: To have complete understanding of a particular climbing move or route.
Diamox: A drug used to inhibit the onset of altitude sickness. Otherwise known as acetazolamide.
Dièdre: A dihedral.
Dihedral: An inside corner of rock, with more than a 90-degree angle between the faces. See also corner and arête.
Direct aid: A type of tension climbing consisting of using one or more belay ropes to haul the leader up to the next point of protection.
Double Rope Technique (DRT): The term denotes the use of two separate ropes, which is true of alpine and rock climbers, but not as much for tree climbers, who usually see it as synonymous with Doubled Rope Technique.
Doubled Rope Technique (DdRT): A method used primarily by tree climbers where the rope passes over a support/limb and continuously slides over the limb as the climber ascends or descends.
Downclimb: To descend by climbing downward, typically after completing a climb.
Dry-tooling: Using tools for ice climbing like crampons and ice axes on rock.
Dulfersitz: A method of rappelling, without mechanical tools, where the uphill rope is straddled by the climber then looped around a hip, across the chest, over the opposite (weak) shoulder, and held with the downhill (strong) hand to adjust the shoulder friction and thus the descending speed.
Dynamic belay: Technique of stopping a long fall using smooth braking to reduce stress on the protection points and avoid unnecessary trauma from an abrupt stop.
Dynamic rope: A slightly elastic rope that softens falls to some extent. Also tend to be damaged less severely by heavy loads. Compare with static rope.
Dynamic motion: Any move in which body momentum is used to progress. As opposed to static technique where three-point suspension and slow, controlled movement is the rule.
Dyno: A dynamic move to grab a hold that would otherwise be out of reach. Generally both feet will leave the rock face and return again once the target hold is caught. Non-climbers would call it a jump or a leap.

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