quartann.adj.

Etymology: As noun < Anglo-Norman quartaine, quarteine and Middle French quartaine (French †quartaine ) quartan fever (1213 in Old French) and its etymon classical Latin quartāna, use as noun (short for febris quartāna quartan fever) of feminine of quartānus (adjective) recurring (by inclusive reckoning) every fourth day < quartus fourth (see quart n.²) + -ānus -an suffix. As adjective < Anglo-Norman quartain, quartein and Middle French quartain (French †quartain ) (of fever) recurring (by inclusive reckoning) every fourth day (13th cent. or earlier in Anglo-Norman in fevre quarteine ) and its etymon classical Latin quartānus. Compare Old Occitan cartana (first half of the 13th cent. as feminine adjective, in febre cartana quartan fever, and perhaps also in 13th cent. as noun), Catalan quartana (late 13th cent. as noun in form †cortana , first half of the 14th cent. as feminine adjective), Spanish cuartana , noun (c1250 as †quartana ), Italian quartana (late 13th cent. or earlier as noun and feminine adjective), and also ( < Latin) Middle Dutch quartane , Middle Low German quārtāne , quārtāna , Middle High German quartāne (German †Quartan ), all in sense ‘quartan fever’. Compare quartern adj. and n.³In use as postmodifying adjective (see sense B. 1a) after similar use in Anglo-Norman fevere quartaine and Middle French, French †fièvre quartaine (13th cent. or earlier in Anglo-Norman) and in their model classical Latin febris quartāna. In double quartan at sense A. 1 after post-classical Latin duplicis quartana (a1364 in the passage translated in quot. a1387, or earlier); compare Spanish †doble quartana (a1284). In sense B. 2 after the literal meaning of classical Latin quartānus.