1911 Encyclopædia Britannica/Ague
AGUE (from Lat. acuta, sharp; sc. febris, fever), the common name given to a form or stage of malarial disease; the ague fit is the cold, shivering stage, and hence the word is also loosely used for any such paroxysm. Simple ague is of much the same type whether in temperate or tropical climates, and may take various forms (quotidian, tertian, quartan), passing into “remittent fever.” The symptoms are discussed, together with causation, &c., in the article Malaria. For “brow-ague” see Neuralgia.