1740, "unwholesome air, air contaminated with the poison producing intermittent and remittent fever," 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). By 1866 it had come to be used of the disease itself (earlier malaria fever, by 1814). The disease, now known to be mosquito-borne, once was thought to be caused by foul air in marshy districts. Replaced native ague.

"pertaining to or arising from malaria," 1830, from malaria + -al (1). Earlier was malarious (1823).

Proto-Indo-European root meaning "to raise, lift, hold suspended." 

It forms all or part of: aerate; aeration; aerial; aero-; aerobics; aerophyte; aerosol; air (n.1) "invisible gases that surround the earth;" airy; aorta; anaerobic; aria; arterial; arterio-; arteriosclerosis; arteriole; artery; aura; malaria; meteor. 

It is the hypothetical source of/evidence for its existence is provided by: Greek aerein "to lift, raise up;" Lithuanian svarus "heavy," sverti "to lift, weigh;" Old English swar, Old Norse svarr, Old High German swar, German schwer "heavy."

Proto-Indo-European root meaning "false, bad, wrong." The exact sense of the root remains uncertain, "since it concerns a collection of largely isolated words in different IE branches" [de Vaan].

It forms all or part of: blame; blaspheme; blasphemous; blasphemy; ‌‌dismal; mal-; malady; malaise; malaria; malediction; malefactor; malefic; malevolence; malevolent; malice; malicious; malign; malison; malversation; mauvais.

It is the hypothetical source of/evidence for its existence is provided by: Avestan mairiia‑, "treacherous;" Greek meleos "idle; unhappy;" Latin male (adv.) "badly," malus (adj.) "bad, evil;" Old Irish mell "destruction;" Armenian mel "sin;" Lithuanian melas "lie," Latvian malds "mistake," possbily also Greek blasphemein "to slander." 

genus of mosquitoes, Modern Latin, coined 1818 by German entomologist Johann Wilhelm Meigen from Greek anopheles "hurtful, harmful," literally "useless," from an- "not, without" (see an- (1)) + ophelos "use, help, advantage," from PIE root *obhel- "to avail" (see Ophelia). So called because it conveys malaria.