Anhydride :: Anhydride (n.) 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..
Anhydrite :: Anhydrite (n.) A mineral of a white or a slightly bluish color, usually massive. It is anhydrous sulphate of lime, and differs from gypsum in not containing water (whence the name)..