aqua (n.)

*akwā-, Proto-Indo-European root meaning "water."

It forms all or part of: aqua; aqua-; aqua vitae; aqualung; aquamarine; aquanaut; aquarelle; aquarium; Aquarius; aquatic; aquatint; aqueduct; aqueous; aquifer; Aquitaine; eau; Evian; ewer; gouache; island; sewer (n.1) "conduit."

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit ap "water;" Hittite akwanzi "they drink;" Latin aqua "water, the sea, rain;" Lithuanian upė "a river;" Old English ea "river," Gothic ahua "river, waters." But Boutkan (2005) writes that only the Germanic and Latin words are sure, Old Irish ab is perhaps related, and "the rest of the evidence in Pokorny (1959) is uncertain."

also aquafortis, old commercial name for "diluted nitric acid," c. 1600, Latin, literally "strong water;" for the elements, see aqua- + fort. Also see aqua. So called for its power of dissolving metals (copper, silver) which are unaffected by other agents.

also aqua-vitae, early 15c., Latin, literally "water of life," an alchemical term for unrefined alcohol. It was applied to brandy, whiskey, etc. from 1540s. For the elements, see aqua- + vital; also see aqua. Compare whiskey, also French eau-de-vie "spirits, brandy," literally "water of life."