The term "fanny" is commonly used in American English to refer to the buttocks, which are the rounded portions of the body located at the back, below the waist. The buttocks consist of muscles and fat and play a crucial role in movement, providing support when sitting and aiding in walking and running. In British English, however, "fanny" refers to the female genitalia, which can lead to confusion between the two dialects. This difference highlights the importance of understanding regional language variations, as the same word can have entirely different meanings depending on the context and location.