ill-defined

Poorly defined; blurry, out of focus; lacking a clear boundary.

An ill-defined dislike, a little like jealousy, arose in Henrietta's mind; a little, however, mitigated by observing that the gentleman instantly caught sight of herself; and that, when not absolutely forced to look at his companion, he looked towards her.

Are you sick, or ill-defined? / Are you lost, or are you just difficult to come by?

Defined in an inconsistent way.