"The Bee's Knees" is a slang phrase that originated in the 1920s, often used to describe something that is considered excellent or outstanding. The expression reflects a playful and whimsical attitude of the era, where many similar phrases emerged to convey admiration or approval. The phrase is thought to derive from the idea that bees produce honey, which is a highly valued substance. In this context, "knees" may refer to the best or most desirable part of something, making "The Bee's Knees" a way to highlight something as top-notch or the best, much like other slang terms from the Roaring Twenties.