This is by no means an exhaustive or even truthful account of those idiosyncratic phrases and terms that infect a climber's vocabulary, but I hope it proves useful.
Arete A vertical edge of rock which may be ascended, it can be pointy or rounded and is often exposed.
Beaching This is applying one's belly to a wide ledge or summit of a climb in an attempt to prevent a rapid descent.
Benightment Climbing in the dark, this may involve part or all of the climb.
Bonus A good thing.
Bold A move, pitch or whole climb which induces extreme fear and/or brown trousers.
Bulgy bits Sections of rock which lean out and attempt to dislodge passing climbers.
Buttress A vertical section of cliff, crag or outcrop which sticks/looms/stands proud out from the rest of the face and leers.
Chickenhead A protruding knob of rock, often on granite. Not to be confused with turtle heads.
Classic A definitive climb of a crag often accompanied with mirror finished holds and queues that would make a Russian shop attendant weep with nostalgia.
Crab A small crustacean with vicious pointy claws.
Dynamic To leap, over extend, rockover or jump for a hold that seems out of reach. This is most widely practised amongst seconds.
Epic An individual climbing experience of a considerable note which provokes a plenum of intense emotional responses, and about a weeks washing.
Esoteric A weird, offbeat and thoroughly dangerous climb where by a climber may metaphorically thrust his genitals into the jaws of death.
Exposure Where a climber is given a marvellous view of the ground without such items as gear spoiling their view.
Flash To complete a climb in an efficient and fast manner, often used in conjunction with "git".
Frigg To ascend a climb by any means possible. This may include rests on the rope, pre-placed gear, or possibly ladders.
Friction A ethereal substance reputed to be found on certain rocks which allows the climber to call upon invisible holds.
Gear The bits a climber takes with them up a climb. These include nuts, friends and sandwiches.
Hat A metaphorical emblem used to symbolise a climbers personality and mental condition.
Jam The application and expansion of ones appendages within cracks as a means of maintaining a grip on the rock. This usually results in skin loss, pain and a desire not to jam again.
Knack The An incantation invoked while completing certain moves which are otherwise impossible.
Knob A cylindrical protuberance which can be gripped and pulled upon, or even lassoed with slings.
Lay back To maximise a holds potential by leaning away from it. Often used in conjunction with thinking of England.
Lob A fall.
Lobbage To fall.
Lumpy bits Areas of rock which aren't smooth.
Mantel shelf To push up onto a ledge so a foot can be placed onto it.
Mantel piece The protruding shelf over a fire place.
Mentos Used to describe a good, but mentally suspect activity, experience or object.
Nails An act or action of extreme boldness, courage or stupidity.
Nut A piece of metal jammed into cracks in the interest of limiting the extent of a lob.
Objective danger Naturally occurring danger outside of a climber's control, including falling rocks, rain, mud, sheep, pigeons, ants, wasp nests and the Stanage beastie.
Ohshitohshitohshitimgonnadie A term used to describe the feeling that occurs before significant lobbage.
Pants A bad thing.
Pear shaped The progressive transfiguration of an occasion from bonus to pants.
Piss poor A not very good thing.
Plenum From the Latin "plenos" meaning full, used in conjunction with everything.
Pointy bits Parts of the rock which stick out, these often have sharp impaling slicing! blood! kill! spurt! spurt! spurt! edges.
Rack A climbers collection of gear, usually distinguished from others with pretty coloured tape tastefully arranged for maximum aesthetic appeal.
Rockover A climbing move which involves placing your feet by your ears then jumping.
Safe A state of mind.
Slack A term used to signal an inattentive second that the rope is not flowing very freely and will shortly be residing around their neck if not reorganised.
Slopey bits Prospective holds that lack a certain reassurance.
Smear To involve the ethereal concept of friction using the position "arse high, feet flat".
Sprag The opposition of finger and thumb within a crack.(not funny, just sounds silly)
Stanage Beastie The Mystical monster of the dark peaks, it is known to dwell in the pallid mists and prey upon isolated climbers.
Tight A flippant remark at a second's generosity with money and drinks, it is often responded to by attempting to pull the leader of the rock. (see slack)
Tricky A selection of climbing which requires "the knack".
Type thing Used as a full stop or for identification of an object (e.g. it's a round type thing).
Udge An inordinately small move between being here and being there, which the brain seems totally unable to comprehend.