ō-yoroi; box-shaped heavy armor used on horseback
Historical term for a type of Japanese armor worn by samurai from the Heian to early Muromachi periods, characterized by a boxy shape and designed primarily for mounted archery.
I saw an exhibition of ō-yoroi at the museum.
Ō-yoroi was mainly used by mounted warriors.
Literally 'great armor'. The term distinguishes this heavy, box-shaped armor from lighter types like 胴丸 and 腹巻. The exact historical derivation of the design is uncertain.