a colorless volatile highly flammable liquid formerly used as an inhalation anesthetic | the purest and most concentrated essence of something |
a medium that was once supposed to fill all space and to support the propagation of electromagnetic waves | the most typical example or representative of a type |
any of a class of organic compounds that have two hydrocarbon groups linked by an oxygen atom | the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies |
the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies | |