Quick Definition
a sign, certain proof
Strong's Definition
a token (as defining a fact), i.e. criterion of certainty
Derivation: neuter of a presumed derivative of (a goal or fixed limit);
KJV Usage: infallible proof
Thayer's Greek Lexicon
τεκμήριον, τεκμηριου, τό (from τεκμαίρω to show or prove by sure signs; from τέκμαρ a sign), from Aeschylus and Herodotus down, that from which something is surely and plainly known; an indubitable evidence, a proof (Hesychius τεκμήριον. σημεῖον ἀληθές): Act_1:3 (Wis_5:11; 3Ma_3:24).
Mounce Concise Greek Dictionary
τεκμήριον tekmērion 1x
a sign, indubitable token, clear proof, Act_1:3
Abbott-Smith Greek Lexicon
** τεκμήριον , -ου , τό
( < τέκμαρ , a mark, sign ),
[in LXX : Wis_5:4 ; Wis_19:13 , 3Ma_3:24 * ;]
a sure sign, a positive proof: Act_1:1-26 (for exx ., v. MM , xxiv).†
SYN.: ἔνδειγμα G1730 , q.v.
Moulton & Milligan — Vocabulary of the Greek NT
τεκμήριον [page 628]
This strong word which AV renders infallible proof in Act_1:3 may be illustrated by an Ephesian inscr. Syll 656 ( = .3 867) .37 ( c . A.D. 160), where it is mentioned as μέγιστον τεκμήριον of the σεβασμός accorded to the goddess Artemis that a month is named after her. Cf. also ib . 929 ( = .3 685) .84 (B.C. 139) μέγιστον καὶ ἰσχυρότατον τεκμήριον , and P Tor I. 1 iv. 11 (B.C. 116) μέγα τι συμβάλλεσθαι τεκμήριον , also viii. 32 . In another Ptolemaic papyrus P Giss I. 39 .9 (B.C. 204 181) τεκμήριον stands beside ὅρκος .
The editors render P Ryl II. 159 .15 (A.D. 31 2) ἵν᾽ ὑπάρχωσι τῇ [Ταχόιτι αἱ παραχωρούμεναι ἄ ]ρουραι σὺν τοῖς ἄλλοις τε̣[κμηρίοις . . ., in order that the arurae ceded may appertain to Tachois with all other titles (i.e. title-deeds ), but in their note they cite the parallel formula P Oxy III. 504 .15 (early ii/A.D.) σὺν τοῖς ἄλλοις σημίοι̣[ς , where the σημεῖα may possibly refer to boundary-marks. It may be added that, according to Hobart p. 184, Galen expressly speaks of the medical distinction between τεκμήριον demonstrative evidence and σημεῖον , stating that rhetoricians as well as physicians had examined the evidence.
For the verb τεκμαίρομαι , see P Ryl II. 74 .5 (A.D. 133 5) where a prefect declares that time will not permit his carrying out two purposes τεκμαίρομαι τὸν χρόνον οὐ̣[χ ἱκανὸν εἶναι εἰ ]ς ἀμφότερα .
Liddell-Scott — Intermediate Greek Lexicon
τεκμήριον τεκμήριον, ου, τό, [Etym: τεκμαίρομαι] like τέκμαρ II, "a sure signs. or token", Hdt. , attic "a positive proof", Aesch. , Plat. , etc.:—in attic Prose τεκμήριον δέ as an independent clause, "now the proof of it is this" (which follows), Thuc. , etc.
STEPBible — Tyndale Abridged Greek Lexicon
τεκμήριον, -ου, τό
(τέκμαρ, a mark, sign), [in LXX: Wis.5:4 19:13, 3Ma.3:24 * ;]
a sure sign, a positive proof: Act.1:1-26 (for exx., see MM, xxiv).†
SYN.: ἔνδειγμα, q.v (AS)