अर्थ : The fifth and highest element after air and earth and fire and water. Was believed to be the substance composing all heavenly bodies.

अर्थ : Any of a class of organic compounds that have two hydrocarbon groups linked by an oxygen atom.

अर्थ : A medium that was once supposed to fill all space and to support the propagation of electromagnetic waves.

अर्थ : A colorless volatile highly flammable liquid formerly used as an inhalation anesthetic.