A cestus is an ancient battle glove, sometimes used in pankration. They were worn as are today's boxing gloves, but were made with leather strips and sometimes filled with iron plates or fitted with blades or spikes, and used as weapons.
The word "cestus" is Latin, an agent noun derived from verb caedere, meaning "to strike", and as such can be reasonably translated as "striker". Despite the final "-s", "cestus" is a singular noun. The Latin plural is caestūs , but in English "cestuses" has been used. 
Early Greek Caestus
The first caestūs in Ancient Greece were series of leather thongs tied over the hand for use in boxing-like competitions. The Greeks also invented a variation called the sphairai which were fitted with cutting blades.
Roman variants included the myrmex (or "limb-piercer") and others featuring various iron plates, spikes, or studs. Caestūs were frequently used in Roman gladiatorial bouts, where otherwise unarmed combatants – mostly slaves – fought to the death. Caestūs boxing became increasingly bloody until hand-to-hand fighting was officially banned in 393 AD.
The Caestus of Boxer of Quirinal
The most famous depiction of the caestus is the Hellenistic sculpture The Boxer of Quirinal. The sitting figure is wearing caestūs on his hands. It is part of the perminent collection of the National Museum of Rome. 
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