What is (a) A salt supposed to be formed by a hydracid and a base. (b) An acid salt. [R.] (c) A hydrous salt; a salt combined with water of hydration or crystallization called?

hydrosalt — (a) A salt supposed to be formed by a hydracid and a base. (b) An acid salt. [R.] (c) A hydrous salt; a salt combined with water of hydration or crystallization. (Webster's 1913.)

Sources