ski

thumb|upright|100px| A shaped alpine ski with relatively little sidecut and classic camber: the tip and tail of an unweighted ski touch the snow while the midsection is in the air. Skis are runners, attached to the user's feet, designed to glide over snow. Typically employed in pairs, skis are attached to ski boots with ski bindings, with either a free, lockable, or partially secured heel. For climbing slopes, ski skins can be affixed to the base of each ski to prevent them from sliding backwards. Originally used as a means of travel over snow, skis have become specialized for recreational and competitive alpine and cross-country skiing.

==Etymology and usage== The word ski comes from the Old Norse word which means "cleft wood," "stick of wood," or "ski". In Old Norse common phrases describing skiing were fara á skíðum (to travel, move fast on skis), renna (to move swiftly) and skríða á skíðum (to stride on skis). In Norwegian this word is usually pronounced . In Swedish, another language evolved from Old Norse, the word is (plural, ; singular: ). The modern Norwegian word ski and the Swedish word skid have largely retained the Old Norse meaning in words for split firewood, wood building materials (such as bargeboards) and roundpole fence.