malaria (n.)

1740, from Italian mal'aria, from mala aria, literally "bad air," from mala "bad" (fem. of malo, from Latin malus; see mal-) + aria "air" (see air (n.1)). Probably first used by Italian physician Francisco Torti (1658-1741). The disease, now known to be mosquito-borne, once was thought to be caused by foul air in marshy districts. Replaced native ague.