Any shortish pole arm with a sword-like blade at one end, used for either stabbing or slashing.
Alternate names: Swordstaves, Glaive, Fauchard, なぎなた, 薙刀, Naginata, 關刀, 关刀, Guan Dao, Kwan Dao, Kuan Tao, 偃月刀, Yanyue Dao
The first video game about Swordstaffs was released on October 1995.
These employ a fighting style generally similar to quarterstaffing, which is dissimilar to regular staff fighting.
Glaive is often misused to describe/name almost any imaginative fictional bladed weapon, though most commonly an enlarged throwing star (possibly inspired by the movie Krull where they just randomly picked an impressive sounding word).