typhus (n.)

1800, literally "resembling typhus," from typhus + -oid. The noun is from 1861, a shortened form of typhoid fever (1845), so called because it originally was thought to be a variety of typhus. Typhoid Mary (1909) was Mary Mallon (d.1938), a typhoid carrier who worked as a cook and became notorious after it was learned she unwittingly had infected hundreds in U.S.

Tiphon "violent storm, whirlwind, tornado," 1550s, from Greek typhon "whirlwind," personified as a giant, father of the winds, probably [Beekes] from or related to typhein "to smoke" (see typhus), but according to Watkins from PIE *dheub- "deep, hollow," via notion of "monster from the depths." The meaning "cyclone, violent hurricane of India or the China Seas" is first recorded 1588 in Thomas Hickock's translation of an account in Italian of a voyage to the East Indies by Caesar Frederick, a merchant of Venice:

concerning which Touffon ye are to vnderstand, that in the East Indies often times, there are not stormes as in other countreys; but euery 10. or 12. yeeres there are such tempests and stormes, that it is a thing incredible, but to those that haue seene it, neither do they know certainly what yeere they wil come. ["The voyage and trauell of M. Caesar Fredericke, Marchant of Venice, into the East India, and beyond the Indies"]

This sense of the word, in reference to titanic storms in the East Indies, first appears in Europe in Portuguese in the mid-16th century. It apparently is from tufan, a word in Arabic, Persian, and Hindi meaning "big cyclonic storm." Yule ["Hobson-Jobson," London, 1903] writes that "the probability is that Vasco [da Gama] and his followers got the tufao ... direct from the Arab pilots."

The Arabic word sometimes is said to be from Greek typhon, but other sources consider it purely Semitic, though the Greek word might have influenced the form of the word in English. Al-tufan occurs several times in the Koran for "a flood or storm" and also for Noah's Flood. Chinese (Cantonese) tai fung "a great wind" also might have influenced the form or sense of the word in English, and that term and the Indian one may have had some mutual influence; toofan still means "big storm" in India.

From the thighs downward he was nothing but coiled serpents, and his arms which, when he spread them out, reached a hundred leagues in either direction, had countless serpents' heads instead of hands. His brutish ass-head touched the stars, his vast wings darkened the sun, fire flashed from his eyes, and flaming rocks hurtled from his mouth. [Robert Graves, "Typhon," in "The Greek Myths"]

Proto-Indo-European root meaning "dust, vapor, smoke." 

It forms all or part of: enthymeme; fewmet; fume; fumigation; funk; perfume; sfumato; typhoid; typhoon; typhus.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dhuma- "smoke, fume;" Greek thymos "spirit, courage, anger," thymiao "fumigate," thymin "incense;" Latin fumus "smoke, steam, fume;" Lithuanian dūmai "smoke" (plural); Old Prussian dumis "smoke;" Old Church Slavonic dymu "smoke;" Middle Irish dumacha "fog;" perhaps Old High German toum "steam, vapor."