quintessence

UK: /kwɪnˈtɛsəns/ US: /kwɪnˈtɛsəns/ ,(kwin tes′əns)

WordReference Random House Learner's Dictionary of American English © 2025

quin•tes•sence /kwɪnˈtɛsəns/   n. [countable* usually singular;
usually: the + ~]

1. the most perfect type or example of something:
   the quintessence of honesty.

WordReference Random House Unabridged Dictionary of American English © 2025

quin•tes•sence  (kwin tes′əns), n. 

1. the pure and concentrated essence of a substance.
2. the most perfect embodiment of something.
3. Philosophy (in ancient and medieval philosophy) the fifth essence or element, ether, supposed to be the constituent matter of the heavenly bodies, the others being air, fire, earth, and water.

• Medieval Latin quīnta essentia fifth essence
• 1400–50; Middle English

quin•tes•sen•tial  (kwin′tə sen′shəl), adj.  quin′tes•sen′tial•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

quintessence / kwɪnˈtɛsəns/ noun

1. the most typical representation of a quality, state, etc
2. an extract of a substance containing its principle in its most concentrated form
3. (in ancient and medieval philosophy) ether, the fifth and highest essence or element after earth, water, air, and fire, which was thought to be the constituent matter of the heavenly bodies and latent in all things

Etymology: 15th Century: via French from Medieval Latin quinta essentia the fifth essence, translation of Greek pemptē ousia