What does "indistinct" refer to?

The term "indistinct" is used to describe something that is not clearly defined, noticeable, or easily distinguishable. In this context, it means something that lacks clarity or precision, leading to a sense of vagueness. When something is described as indistinct, it may be difficult to see, hear, or understand, which aligns with the idea of being vague. This contrasts with the other options, which imply clarity and recognition. For example, "clearly defined," "well-known," and "easily recognizable" all suggest a sense of clarity and distinctness that directly opposes the meaning of "indistinct." Therefore, choosing "vague" accurately captures the essence of the term.