The quintessence of something is its perfect, ideal example. Some people say that the quintessence of American cuisine is the hamburger. Vegetarians may beg to differ.
Ancient Greek philosophers claimed there were five elements: earth, water, air, fire, and a fifth substance that made up objects in the heavens. This idea was passed down through the ages to Latin-speaking scholars who called the fifth element quintessence — from the Latin words quintus, meaning “fifth,” and essentia, meaning “being.” Eventually, the word’s meaning evolved into our modern definition of an ideal, a potentially heavenly example of something — you know, like a hamburger.