Quick Definition
quickness, speed
Strong's Definition
a brief space (of time), i.e. (with G1722 (ἐν) prefixed) in haste
Derivation: from the same as G5036 (ταχύς);
KJV Usage: + quickly, + shortly, + speedily
Thayer's Greek Lexicon
τάχος, τάχους, τό, from Homer down, quickness, speed: ἐν τάχει (often in Greek writings from Aeschylus and Pindar down), quickly, shortly, Act_12:7; Act_22:18; (); Rom_16:20; speedily, soon (German in Bälde), Luk_18:8; 1Ti_3:14 L Tr WH; Rev_1:1; Rev_22:6.
Mounce Concise Greek Dictionary
τάχος tachos 8x
swiftness, speed, quickness; ἐν τάχει , with speed, quickly, speedily; soon, shortly, Luk_18:8 ; Act_25:4 ;
hastily, immediately, Act_12:7 ; Act_22:18 ; Rom_16:20 ; 1Ti_3:14 ; Rev_1:1 ; Rev_22:6
Abbott-Smith Greek Lexicon
τάχος , -ους , τό ,
[in LXX chiefly for parts and derivatives of H4116 ;]
swiftness, speed. Adverbially, ἐν τ . ( < ταχέως ), quickly, speedily, soon: Luk_18:8 , Act_12:7 ; Act_22:18 ; Act_25:4 , Rom_16:20 , 1Ti_3:14 , Rev_1:1 ; Rev_22:6 .†
Moulton & Milligan — Vocabulary of the Greek NT
τάχος [page 627]
quickness : PSI IV. 326 .12 (B.C. 261 0) ἔντειλαι τῶι παρά σου , ἵνα τὸ τάχος γέ [νη ]τ̣αι , and P Oxy I. 59 .15 (A.D. 292) ἵν᾽ . . . ᾖ τάχος ἐκδημῆσαι , in order that no time be lost in his departure (Edd.) : cf. PSI IV. 444 .11 (iii/B.C.) πειρῶ δέ μοι ὅ τι τάχο̣ς̣ γράψ̣ειν Ἔρρωσο , and P Bouriant 10 .22 (B.C. 88) ἀσ ]φαλισάμενος [μέ ]χρι τοῦ καὶ [ἡμᾶ ]ς ὅτι τάχος [ἐπι ]βαλεῖν πρὸς σέ .
The word is common in adverbial phrases with a preposition, e.g. P Oxy I. 62 verso .18 (iii/A.D.) τὴν ἐμβολὴν ποιῆσαι διὰ τάχους , to do the lading quickly (Edd.), ib . VI. 892 .9 (A.D. 338) διὰ ταχέων ταῦτα ἐκκόψας παρενεχθῆναι , with all speed to get the timber cut and delivered (Edd.); PSI IV. 380 .14 (B.C. 249 8) καλῶς δ᾽ ἂν ποιήσαις ἐν τάχει (cf. Luk_18:8 , al .) αὐτὸν ἀποστείλας , P Giss I. 69 .10 (A.D. 118 9) πᾶσαν τὴν . . . [κ ]ρειθὴν ἐν τάχει αὐτῷ ἐπιστεῖλαι , and P Oxy VII. 1069 .4 (iii/A.D.) καλῶς ποιήσεις ἀναγκάσε̣ γενέστε ( l . ἀναγκάσαι γενέσθαι ) μου τὸ κειθώνε̣[ι ]ν ( l . κιθώνιν ) τὸ λευκὸν κατὰ τάχονυύς , you will do well to have my white tunic made quickly (Ed.).
Liddell-Scott — Intermediate Greek Lexicon
τάχος τάχος, ος, εος, τό, [Etym: τα^χύς] "swiftness, speed, fleetness, velocity", Il. , Plat. τ. φρενῶν "quickness" of temper, "hastiness", Eur. τάχος is often used in Adverbial phrases for ταχέως, absol. in acc., Aesch. , etc.: —with Preps., ἀπὸ τάχους Xen. ; διὰ τάχους Soph. , etc.; ἐν τάχει Aesch. , etc.; εἰς τάχος Xen. , etc.; κατὰ τάχος Hdt. , Thuc. ; μετὰ τάχους Plat. ; σὺν τάχει Soph. :—also with relatives, ὡς τάχος, like ὡς τάχιστα, Hdt. , Aesch. ; so, ὅ τι τάχος Hdt. , Soph. ; ὅσον τάχος Soph. :—also, ὡς τάχεος εἶχεν ἕκαστος as each was off "for speed", i. e. as quickly as they could, Hdt. ; ὡς εἶχον τάχους Thuc.
STEPBible — Tyndale Abridged Greek Lexicon
τάχος, -ους, τό
[in LXX chiefly for parts and derivatives of מָהַר ;]
swiftness, speed. Adverbially, ἐν τ. (ταχέως), quickly, speedily, soon: Luk.18:8, Act.12:7 22:18 25:4, Rom.16:20, 1Ti.3:14, Rev.1:1 22:6.†
(AS)