noun

1. Archaic unwholesome or poisonous air, as from marshy ground; miasma

2. Etymology: from the former notion that it was caused by the bad air of swamps

   an infectious disease, generally intermittent and recurrent, caused by any of various protozoans (genus Plasmodium) that are parasitic in the red blood corpuscles and are transmitted to humans by the bite of an infected anopheles mosquito: it is characterized by severe chills and fever

Etymology: It, contr. < mala aria, bad air: see mal- & aria