Definition of cataphracts:
(n) :
(military, historical) Defensive armour covering the entire body of a soldier and often the soldier's horse as well, especially the linked mail or scale armour of some eastern nations.
(n) :
(military, historical) A soldier (especially a horseman) covered with a cataphract (etymology 1, sense 1).
(n) :
A galley with the upper tier of rowers shielded.
(adj) :
(nautical, historical) Of a galley such as a trireme: with the upper tier of rowers shielded rather than exposed.
(n) :
(ichthyology, by extension, obsolete) An outer covering of some fish resembling armour or plate.