A lance is a thrusting spear designed to be used by a mounted warrior or cavalry soldier (lancer). In ancient and medieval warfare, it evolved into the leading weapon in cavalry charges, and was unsuited for throwing or for repeated thrusting, unlike similar weapons of the javelin and pike family typically used by infantry. Lances were often equipped with a vamplate, a small circular plate to prevent the hand sliding up the shaft upon impact, and beginning in the late 14th century were used in conjunction with a lance rest attached to the breastplate. Though best known as a military and sporting weapon carried by European knights and men-at-arms, the use of lances was widespread throughout Asia, the Middle East, and North Africa wherever suitable mounts were available. Lancers of the medieval period also carried secondary weapons such as swords, battle axes, war hammers, maces and daggers for use in hand-to-hand combat, since the lance was often a one-use-per-engagement weapon; assuming the lance survived the initial impact without breaking, it was often (depending on the lance) too long, heavy, and slow to be effective against opponents in a melee.
The name is derived from the word lancea — the Roman auxiliaries' javelin or throwing spear; although according to the OED, the word may be of Iberian origin. Also compare λόγχη (lónkhē), a Greek term for "spear" or "lance".
A lance in the original sense is a light throwing spear or javelin. The English verb to launch "fling, hurl, throw" is derived from the term (via Old French lancier), as well as the rarer or poetic to lance. The term from the 17th century came to refer specifically to spears not thrown, used for thrusting by heavy cavalry, and especially in jousting. The longer types of thrusting spear used by infantry are usually referred to as pikes.
The Byzantine cavalry used lances (kontos or kontarion) almost exclusively, often in mixed formations of mounted archer and lancer formations (cursores et defensores).