Which term refers to flat or raised skin lesions with rounded, well-defined borders?

The term that specifically refers to flat or raised skin lesions with rounded, well-defined borders is "nevi." Nevi are commonly known as moles and can be either flat or raised. They typically have a clear and defined border, distinguishing them from other types of skin lesions.

Understanding the characteristics of nevi, including their pigmentation and shape, helps in differentiating them from other skin formations. For instance, while papules are small, solid, elevated lesions, they do not have the same well-defined characteristics as nevi. Macules are flat and usually not raised, serving as a distinct category due to their lack of elevation. Warts, on the other hand, are caused by the human papillomavirus and have a different appearance, often being rough and irregularly shaped. All these factors highlight why "nevi" is the appropriate term for flat or raised skin lesions with rounded, well-defined borders.