(of an image etc) not clearly defined or not having a sharp outline; faint or dim / (of a thought, idea etc) hazy or vague / (of speech) difficult to understand through being muffled or slurred

The property of being indistinct. / An indistinct thing.

That has no distinguishing characteristics

(obsolete) indistinguishable

The quality of being indistinctive.

The fact of not distinguishing or making distinctions; failure to perceive or make a difference.

In an indistinct manner

plural of indistinctness

plural of indistinction

In an indistinct manner.