Indecipherable [adjective]

Although Valentine and his two comrades might interrogate the desert, it remained dumb and indecipherable as a closed book.

And what a strange and indecipherable "crypto-porticus" would the "Twopenny Tube" prove to some future Middleton of the ages?

Stoddard looked down at the shameful old man with eyes that were indecipherable.

But what an indecipherable riddle was this building, standing on a site of the Eocene period!

It satisfied in some measure the vague, indecipherable yearning of my soul; and it was the same with him.

The staff is fully occupied upon the work in hand, and cannot wade through pages of often indecipherable hand-writing.

From this she derived a feeling, which she resented, of having witnessed a scene fraught with significance indecipherable to her.

Besides this there were one or two indecipherable words scratched on it, and three common names rather more clearly cut.

He scrawled a nearly indecipherable "Burns" at the bottom, folded the slip and handed it to his friend.

It is so tattered that one stanza, the last, is indecipherable and had to be omitted.