A spear was a primitive weapon, usually made from a wooden shaft and a metal head. It could be used in melee combat to stab an opponent, or from range by throwing.
The spear was a weapon favoured by humans prior to the introduction of gunpowder. The tribesmen that the First Doctor and his companions encountered in 100,000 BC used spears and threw them at the TARDIS. (TV: An Unearthly Child) Irongron's men also used spears. (TV: The Time Warrior) Spears were also useful practically. Gilgamesh hunted with a spear. (PROSE: Timewyrm: Genesys)
On Delta Magna, the Swampies carried spears and used them in a ceremonious capacity during their worship of Kroll. (TV: The Power of Kroll) On an unnamed planet John was captured by a hostile native tribe armed with spears. (COMIC: The Didus Expedition)