Ill defined.

There could be ill define margins in tissues under a microscope. A pathologist can pick 'em up.

There may be ill define logic in an argument, a critic can catch it.

There could be ill define lines under your eyes, an observant can point that out.

But when there is ill define pain prevailing inside you, there aren't many who could reach to it.

It just persists.

at times for eternity.