1. embodiment: the purest or most perfect example of something
2. chemistry extract: the purest extract or essence of a substance, containing the substance's properties in their most concentrated form
3. philosophy fifth element: in ancient and medieval philosophy, the fifth element after earth, air, fire, and water. Heavenly bodies were said to be made of it.
4. cosmology hypothetical repulsive force: a hypothetical repulsive force in cosmology that permeates the whole of space and counteracts the force of gravity
[15th century. Via French< medieval Latin quinta essentia "fifth essence"]
