Abbott-Smith Manual Greek Lexicon
τεκμήριον (G5039)
1 ** τεκμήριον , -ου, τό ( τέκμαρ , a mark, sign ), [in LXX: Wi 5:4 19:13 , III Mac 3:24 * ;] a sure sign, a positive proof : Ac 1:3 (for exx., v. MM, xxiv).† SYN. : ἔνδειγμα , q.v
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain