The term "amorphous ring" can be replaced by several different synonyms, each providing a slightly different nuance. A possible alternative is "shapeless loop" which emphasizes the lack of defined form. "Indistinct band" is a similar synonym, describing the ring's indistinguishable qualities. "Formless circle" also conveys this idea, highlighting the absence of structure. "Blurry halo" may be used to suggest a hazy or nebulous effect. Finally, "unstructured hoop" highlights the ring's undefined nature. Each of these synonyms can be used in place of "amorphous ring" depending on the context, tone, and intended meaning.