Lexical Definition

‎ταχύς‎ tachýs (takh-oos') quick ^G:A
of uncertain affinity

swift.

• fleet, i.e. (figuratively) prompt or ready

Abbott-Smith

ταχύς, -εῖα, -ύ [in LXX chiefly for מָהַר pi. ;]
quick, swift, speedy: opp. to βραδύς, Ja 1:19.†

Abbott-Smith References

Liddell-Scott-Jones

ταχύς [ῠ], εῖα, ύ:

__I of motion, swift, fleet, opposed to βραδύς,
__I.1 of persons and animals, either absolutely, [Refs 8th c.BC+]; or more fully, πόδας ταχύς [Refs]; ταχὺς ἔσκε θέειν [Refs 8th c.BC+]; θείειν τ. [Refs 8th c.BC+]; κύνες, ἔλαφος, πτώξ, ἵππος, [Refs 8th c.BC+]; τ. βαδιστής a quick walker, [Refs 5th c.BC+]; σφοδροὶ καὶ τ. [Refs 5th c.BC+]
__I.2 of things, τ. πόδες [Refs 8th c.BC+]; τ. ἰός, ὀϊστοί, [Refs 8th c.BC+]; νῆες, τριήρεις, [Refs 5th c.BC+]
__II of thought and purpose, quick, hasty, φρονεῖν γὰρ οἱ ταχεῖς οὐκ ἀσφαλεῖς [Refs 5th c.BC+]infinitive, βλάπτειν τ. [Refs 5th c.BC+]; τὸ ταχύ speed, haste, [Refs 5th c.BC+]
__II.2 of actions, events, etc., rapid, sudden, πήδημα [Refs 5th c.BC+]; ᾅδης, μόρος, [Refs 5th c.BC+]; short, τ. ἐλπίδες fleeting hopes, [Refs 5th c.BC+]; τ. διήγησις short, rapid, [Refs 4th c.BC+]
__B adverb,
__B.1 regular τᾰχέως, quickly, opposed to βραδέως, [Refs 8th c.BC+]:—rarely in sense perhaps [Refs 2nd c.BC+]
__B.2 the adverb is also expressed by periphrastic, διὰ ταχέων in haste, [Refs 5th c.BC+]
__B.3 neuter ταχύ as adverb, [Refs 5th c.BC+]; ἤδη ἤδη τ. τ. [Refs 3rd c.AD+]; ἄρτι ἄρτι τ. τ. [Refs 2nd c.AD+]; also τάχα (which see).
__B.4 the adjective ταχύς is frequently construed with Verbs, where we should use the adverb, ταχέες δ᾽ ἱππῆες ἄγερθεν [Refs 8th c.BC+]; δεῦρ᾽ ἀφίξεται τ. [Refs 5th c.BC+]
__C Degrees of Comparison:
__C.I comparative:
__C.I.1 the form τᾰχύτερος, α, ον, is used by [Refs 5th c.BC+]; also in [Refs 4th c.BC+], but not in good Attic dialect; ταχύτερον as adverb, [Refs 5th c.BC+]
__C.I.2 the more usual form is θάσσων, neuter θᾶσσον, genitive ονος, Attic dialect θάττων, neuter θᾶττον, [Refs 8th c.BC+], etc.:—neuter as adverb, frequently in [Refs 8th c.BC+]; θᾶσσον ἂν.. κλύοιμι sooner, i.e. rather, would I hear, [Refs 5th c.BC+]; θᾶσσον also often stands for the Positive, [Refs 8th c.BC+]; οὐ θᾶσσον οἴσει; i.e. make haste and bring, [Refs 5th c.BC+]; θᾶττον νοήματος quicker than thought, [Refs 5th c.BC+]; with a conjunction, ὅτι θᾶσσον, like{ὅτι τάχιστα}, [Refs 3rd c.BC+]; ἐπειδὴ θᾶττον συνεσκότασεν as soon as.. , [Refs 5th c.BC+]; ἐὰν or ἢν θ. as soon as.. , [Refs 5th c.BC+]; ἂν θ. [Refs 4th c.BC+]; εἰ θ. [Refs 5th c.BC+]; ὡς θ. [Refs 2nd c.BC+]; θ. rarely = sooner than, before, ἐξήλαυνον μεσημβρίας οὐ πολλῷ τινι θ. [Refs 2nd c.AD+]
__C.I.3 the form ταχίων [ῑ], neuter ιον, is frequently in late Prose, as [LXX+5th c.BC+]; but condemned by [Refs 2nd c.AD+]; τὴν ταχίονα τῆς τροφῆς παράθεσιν earlier, sooner, [Refs 2nd c.AD+] — adverb τάχιον earlier, πλέεται.. περὶ τὸν Σεπτέμβριον μῆνα.., οὐδὲν δὲ κωλύει κἂν τ. [Refs]; τ. τῆς ὑποσχέσεως sooner than they had promised, [Refs]; τ. τοῦ παραγγέλματος [Refs 1st c.AD+]; formerly, ἐπεσκεύασαν τὸ παρόχιον,.. τ. γενόμενον γυμνάσιον [Refs 2nd c.AD+]; compare above 2 near the end
__C.II superlative:
__C.II.1 the form ταχύτατος is rare, ταχύτατα ἅρματα [Refs 5th c.BC+]; ταχύτατα as adverb, [Refs 5th c.BC+]; but both passages have been corrected.
__C.II.2 the usual form is τάχιστος, η, ον, used by [Refs 8th c.BC+] as adverb, most quickly, most speedily, ὅττι τάχιστα as soon as may be, as soon as possible, [Refs 8th c.BC+]; so ὅσον τ. [Refs 5th c.BC+]; ᾳ (probably) τ. [Refs 5th c.BC+]; ὅπως τ. [Refs 5th c.BC+]; ὡς τ. [Refs 5th c.BC+]: these are elliptically phrases, as may be seen from the following examples, ὡς δυνατόν ἐστι τάχιστα [Refs 5th c.BC+]; ᾗ δυνατὸν τ. [Refs]; ὡς or ᾗ ἠδύνατο τ. [Refs]; ὡς δύναιτο τ. [Refs 5th c.BC+]; ὡς or ᾗ ἂν δύνωμαι τ. [Refs 5th c.BC+]
__C.II.2.b τάχιστα after Particles of Time, as soon as, ἐπεὶ (Ionic dialect ἐπεί τε) τάχιστα [Refs 5th c.BC+]; ἐπειδὴ τ. [Refs 5th c.BC+]; ἐπεὰν τ. [Refs 5th c.BC+]; ἐπὰν τ. [Refs 5th c.BC+]; ἐπειδὰν τ. [Refs]; ὅταν τ. [Refs]. separated by one or more words, ὡς ἡμέρη τ. ἐγεγόνεε [Refs 5th c.BC+]; ὡς γὰρ τ. εἰσῆλθον [Refs 4th c.BC+]; ὅπως τ. [Refs 4th c.BC+] —the same notion is sometimes expressed by the participle, ἀπαλλαγεὶς τάχιστα, ={ὡς ἀπηλλάγη τ}., [Refs 1st c.AD+]
__C.II.3 frequently also in Prose, τὴν ταχίστην (in full, τὴν τ. ὁδόν [Refs 5th c.BC+] as adverb, by the quickest way, i.e. most quickly, [Refs 5th c.BC+] deñgti, Lett. diêgt, both = 'run quickly', Polish dążyć 'hurry'.)

_{LSJ Scripture Refs: John.20.4}