What does aqua mean?
The definition of aqua
A”qua, n.
Etym: [L. See Ewer.]

Water; — a word much used in pharmacy and the old chemistry, in various signification, determined by the word or words annexed. Aqua ammoniæ, the aqueous solution of ammonia; liquid ammonia; often called aqua ammonia.

— Aqua marine, or Aqua marina. Same as Aquamarine. — Aqua regia.
Etym: [L., royal water] (Chem.), a very corrosive fuming yellow liquid consisting of nitric and hydrochloric acids. It has the power of dissolving gold, the “royal” metal.
— Aqua Tofana, a fluid containing arsenic, and used for secret poisoning, made by an Italian woman named Tofana, in the middle of the 17th century, who is said to have poisoned more than 600 persons. Francis. — Aqua vitæ
Etym: [L., water of life. Cf. Eau de vie, Usquebaugh], a name given to brandy and some other ardent spirits. Shak.