A thing that is the most perfect example of its type; the most perfect embodiment of something; epitome, prototype.
A pure substance.
The fifth alchemical element, or essence, after earth, air, fire, and water that fills the universe beyond the terrestrial sphere.
The essence of a thing in its purest and most concentrated form.
A hypothetical form of dark energy postulated to explain observations of an accelerating universe.
To reduce to its purest and most concentrated essence.