plural of skew arch

plural of safety arch

plural of haemal arch

plural of scheme arch

plural of flying arch

(archaeology, US, usually capitalized) A general term for the prehistoric period intermediate between the earliest period (‘Paleo-Indian’, ‘Paleo-American’, ‘American‐paleolithic’, &c.) of human presence in the Western Hemisphere, and the most recent prehistoric period (‘Woodland’, etc.).

Of or characterized by antiquity; old-fashioned, quaint, antiquated.

(history) The son or male-line grandson of an emperor of the Austro-Hungarian Empire. / (history) The ruler of an archduchy, in particular the Archduchy of Austria.

A powerful angel that leads many other angels, but is still loyal to a deity, and often seen as belonging to a particular archangelical rank or order within a greater hierarchy of angels. (Judeo-Christian examples: Gabriel, Michael, Raphael, Uriel).

(computer hardware) The conceptual structure around which a given computer is designed. / (computer hardware) The science of computer design.