Definition of indiscernible:
undetectable, indistinguishable, indistinct, faint, blurred, imponderable, insensible, obscure, impalpable, senseless, inconspicuous, feeble, ill-defined, unaffected, unnoticeable, intangible, subtle, knowledge, fuzzy, imperceptible, vague, inappreciable, unperceivable.
When he tried to see who it was, there was nothing to see; the presence existed there as a centre in a sphere, immeasurable and indiscernible; sometimes he thought it was Mary, sometimes he thought it Henry Buxton, sometimes Isabel- once even he assured himself it was Mistress Margaret, and once James Maxwell- and with the very act of identification came indecision again.- "By What Authority?", Robert Hugh Benson.
In the fading twilight the so- called ranch stood vaguely outlined, the nature of its log and adobe walls indiscernible, its mill and the still house looming vaguely over the main building against the darker background of the slope.- "Bring Me His Ears", Clarence E. Mulford.
The thin fishing line was indiscernible against the slimy side of the pit, and Colwyn realised that he would never have discovered it had it not been for the lucky accident which had exposed the peg to which the line was anchored.- "The Shrieking Pit", Arthur J. Rees.