A spetum is a polearm that was used in Europe during the 13th century. Other names include chauve souris, corseca, corsèsque, korseke, runka, and rawcon. It consists of a pole, some NaNfeet long, on which is mounted a spear head with two projections at its base. Many variations of this design flourished over time; some feel that the ranseur is a variation of the spetum. According to antiquarian John Hewitt, the spetum is a variation of the partisan.[1] The spetum is usually distinguished from the ranseur and partisan by its "prongs" being single edged and used for slashing. The main blade is NaNinches long [I have not found any sources supporting this measurement, the spetum shown in the image's head is measured at 46 in (118.1 cm) meaning the blade is only marginally shorter than 46 inches], and the side blades are only about half that length and are set at acute angles.
The design of a spetum is for combat. The main blade is long enough to destroy any significant organ in the human body with a thrust. The side blades could bind weapons, similar to a jitte or sai. The blunt backs of the side blades give the spetum a variety of uses such as tripping and knocking aside shields while providing far more strength to the sharpened side and points than is possible with a dual-edged construction.
The word spetum comes meaning "spit".