τεκμήριον (tekmḗrion|tek-may'-ree-on|noun|proof)
[Grk] τεκμήριον LN: 28.45 GK: G5447
Derivation: neuter of a presumed derivative of τεκμάρ (a goal or fixed limit);
Strong's: a token (as defining a fact), i.e. criterion of certainty
KJV: --infallible proof.