What is an oxide of a nonmetallic body or an organic radical, capable of forming an acid by uniting with the elements of water; -- so called because it may be formed from an acid by the abstraction of water called?

anhydride — An oxide of a nonmetallic body or an organic radical, capable of forming an acid by uniting with the elements of water; -- so called because it may be formed from an acid by the abstraction of water. (Webster's 1913.)