Indistinguishable
Pronunciation : In`dis*tin"guish*a*ble
Part of Speech : a.
Definition : Defn: Not distinguishable; not capable of being perceived, known, or discriminated as separate and distinct; hence, not capable of being perceived or known; as, in the distance the flagship was indisguishable; the two copies were indisguishable in form or color; the difference between them was indisguishable.
Source : Webster's Unabridged Dictionary, 1913