"fine, dry particles of earth or other matter so light that they can be raised and carried by the wind," Old English dust, from Proto-Germanic *dunstaz (source also of Old High German tunst "storm, breath," German Dunst "mist, vapor," Danish dyst "milldust," Dutch duist), from PIE *dheu- (1) "dust, smoke, vapor" (source also of Sanskrit dhu- "shake," Latin fumus "smoke").
Meaning "elementary substance of the human body, that to which living matter decays" was in Old English, hence, figuratively, "mortal life." Sense of "a collection of powdered matter in the air" is from 1570s. Dust-cover "protective covering to keep dust off" is by 1852; dust-jacket "detachable paper cover of a book" is from 1927. To kick up the (or a) dust "cause an uproar" is from 1753, but the figurative use of dust in reference to "confusion, disturbance" is from 1560s. For bite the dust see bite (v.).