epitome
The perfect example of a certain quality or type.
The epitome of something is the perfect example of it, the thing that shows its qualities most clearly and completely. When someone calls your friend “the epitome of kindness,” they mean your friend represents kindness in its truest, most complete form.
Today, we use it to describe someone or something that perfectly represents a quality or type. A championship team might be called the epitome of teamwork if every player supports the others flawlessly. A beautifully designed building could be the epitome of modern architecture.
Epitome means being the best or most characteristic example, the one that shows all the key features most clearly. If your teacher says a student's essay is the epitome of clear writing, she means it demonstrates everything that makes writing clear: simple language, logical organization, and well-explained ideas.
You might hear someone say a villain in a story is “the epitome of evil” or a scientist is “the epitome of curiosity.” They're saying these people embody those qualities so completely that studying them would teach you a lot about what those qualities mean.