Webster's Revised Unabridged Dictionary · 1913

Ski

Ski (skē) , noun

[Danish ski; Icelandic skīe a billet of wood. See Skid.]

A long, flat, narrow runner made of wood, plastic or metal, curved upwards in front, having a fitting allowing it to be attached to the foot, and used for gliding or sliding over snow. Commonly used in the plural, to designate the pair.