undulation a swell or wave in the snow.
traversing a diagonal run across a slope.
washboard a series of small, bumpy waves in the snow.
wedelns a series of very fast and slight changes in direction made by flexing the body joints.
skydiving
automatic opener a device calibrated to deploy automatically a parachute at 1,000 to 1,200 feet, used with student jumpers.
auxiliary chute a reserve parachute.
bag deployment the fabric container enclosing the parachute canopy.
batwings rigid or semirigid surfaces attached to the arms and body to facilitate gliding and slow descent, used illegally.
breakaway the jettisoning of the main parachute to deploy the reserve chute; the cutting of suspension lines to release the canopy.
cloth extensions sections of fabric sewn into the armpits and crotch area to facilitate gliding and to slow descent; not the same as batwings.
crabbing directing the descending parachute sideways to the wind.
delta position a freefall position in which the arms are held back at the sides with the head held low, to increase the rate of descent.
deployment the release and unfurling of the parachute from its pack.
deployment device a sleeve or bag that contains the canopy, slows its opening and reduces shock.
docking joining hands (or other body parts) with another diver in midair.
drop altitude the altitude at which a skydiver jumps.
drop zone a specified area where a skydiver plans to land.
exit point the point in the air, often over a landmark on the ground, where a jumper exits the plane.
freefall the portion of the jump in which the parachute is not yet deployed. Also, any jump in which the chute is deployed at the skydiver's discretion, as distinguished from a static line jump.
frog position a freefall position in which the jumper assumes a spread-eagle posture with arms upraised.
glide horizontal movement through the sky.
groundhog any nonjumping spectator on the ground.
hank to pull or yank on a steering line.
harness the webbing and strapping that cradles the jumper and connects with the suspension lines.
holding directing the canopy against the wind to slow ground speed.
hop 'n' pop pulling the ripcord immediately after exiting from the plane.
inversion a deployment malfunction in which the canopy becomes turned completely or partially inside out.
jumpmaster an experienced jumper and jump leader; one who oversees the jumps of students.
line-over a deployment malfunction in which one or more lines get caught up over the top of the canopy. Also known as a Mae West.
opening point the point in the air at which the jumper should pull the ripcord in order to land within the specific jump zone.
opening shock the shock or pull felt by the jumper when the chute opens.
oscillation the swinging back and forth of a jumper under a descending canopy, usually occurring during turns.
pack collective term for the parachute assembly, including the container, canopy, connector links, risers, suspension lines, and reserve chute.
pack tray the container part that holds the lines when stowed.
paraboots special shock-absorbent boots worn by jumpers.
pilot chute a small parachute used to help deploy the main parachute.
PLF parachute landing fall; a method of landing in which impact is distributed across several points of the body instead of to the feet and ankles alone.
poised exit an exit made from an airplane wing or strut.
relative work working with others in midair to create formations or to conduct stunts.
reserve the auxiliary chute.
running directing the parachute to fly with the wind to increase ground speed.
smoke flares used to make the jumper easier to spot from spectators on the ground.
spotting choosing the airplane course and a ground landmark over which to jump in order to land at a desired location.
stall the loss of lift.
static line a line attached from the aircraft to the parachute; it automatically deploys the parachute as soon as the jumper exits the plane.
steering lines short lines connected to the suspension lines, used to steer the canopy. Also known as toggle lines.
streamer a deployment malfunction in which part of the canopy clings together and fails to unfurl.
suspension lines the cords connected to the harness from the canopy.
terminal velocity the fastest speed a body can reach while dropping through the air, approximately 120 miles per hour, reached about 12 seconds after exiting an airplane, depending on body position.
toggle lines see steering lines.
tracking assuming the best body position for horizontal movement.
wind drift indicator a weighted strip of crepe paper, usually about 20 feet long, dropped out of an airplane to determine the amount of drift a jumper can expect during descent.
snowboarding
air a reference to being or getting airborne, often called catching air.
alley-oop a 180° rotation.
backside where the heels are planted on a snowboard. bail to crash or fall.
boarder cross competition a race in which competitors run a gated course composed of various jumps and turns.
bone to ride with one or both legs straightened. bonk to strike a rock or log.
boosting getting up in the air off a jump. caballerial a rotation of 360°. carve to make a turn. catching air boosting.
chatter board vibrations produced at high speeds and through turns, reducing control.
corduroy a surface of finely ridged snow, like corduroy pants, created by the grooming of a snowcat.
crater to crash, especially when one leaves a hole in the snow afterward.
crippler air a stunt composed of a 90° rotation, followed by a flip, and another 90° rotation.
cruise an easy, straightforward run without tricks or stunts.
dampening a method of reducing chatter or vibrations by laminating rubber into the board.
double-handed grab a stunt in which the snowboard is grabbed with both hands while in midair.
dragon a machine used to groom half-pipes.
duckfoot a stance in which the toes are pointed outward.
effective edge running the length of the board, the metal edge that comes in contact with the snow.
fakie, ride to ride backward, with the foot that is normally planted in back in the front.
540 air a 540° rotation in which the boarder ends up riding backwards or fakie.
flail to ride wildly out of control, especially with windmilling arms.
flying squirrel air bending at the knees and grabbing the back of the board with both hands while in midair.