adjective. If you describe something as ill-defined, you mean that its exact nature or extent is not as clear as it should be or could be. ... staff with ill-defined responsibilities. Synonyms: unclear, vague, indistinct, blurred More Synonyms of ill-defined.

What does it mean if something is ill defined?

: not easy to see or understand The property's borders are ill-defined.

What is a synonym for ambiguous?

Some common synonyms of ambiguous are cryptic, dark, enigmatic, equivocal, obscure, and vague.