What term describes something that is clear or distinct to the eye or ear?

The term "plain" refers to something that is clear or distinct to the eye or ear, indicating that it is easily perceived and understood without confusion. This clarity can apply to various forms of expression, whether it's visual or auditory. When something is described as plain, it conveys a straightforwardness that makes it comprehensible at a glance, making it effective for communication and recognition.

In contrast, the other terms tend to imply a lack of clarity. "Obscure" suggests that something is not clearly expressed or understood, which directly opposes the idea of being plain. "Ambiguous" refers to something that can be interpreted in multiple ways, lacking a clear meaning or direction. Lastly, "vague" denotes a lack of precision or clarity, making it difficult to grasp the intended message or image. Thus, while these other terms imply confusion or uncertainty, "plain" effectively captures the essence of clarity.