Lexical Definition

‎ἐπειδή‎ epeidḗ (ep-i-day') since ^G:CONJ
from ‎ἐπεί‎ and ‎δή‎

after that, because, for (that, -asmuch as), seeing, since.

• since now, i.e. (of time) when, or (of cause) whereas

Abbott-Smith

ἐπει-δή
conj.;
1. of time, when now, after that: Lk 7:1 (WH, txt.).
2. Of cause, seeing that, forasmuch as: Lk 11:6, Ac 13:46 (WH, txt., RV) Ac 14:12 15:24, I Co 1:21, 22 14:16 15:21, Phl 2:26.†

Abbott-Smith References

Liddell-Scott-Jones

ἐπειδή,

conjunction, both temporal and causal; also ἐπειδή, ἐπειδήτε. OF TIME (ἐπειδή is more frequently in this sense in Prose), after that, since, when, from [Refs 8th c.BC+]

__I with Ind.,
__I.1 of a definite occurrence in past time, mostly with aorist, ἐπειδή π᾽ εὔξαντο after they had prayed, [Refs 8th c.BC+]after [Refs 5th c.BC+]: rarely with imperfect, ἐπειδὴ εἱστιώμεθ᾽ [Refs 5th c.BC+]pluperfect, ἐπειδὴ ἐξηπάτησθε.. after you had been deceived.., [Refs 4th c.BC+]; but generally the aorist is found, the pluperfect being used only for special emphasis: with imperfect to express an action not yet complete, ἐπεὶ ὑπηντίαζεν ἡ φάλαγξ καὶ ἡ σάλπιγξ ἐφθέγξατο after the phalanx began to advance and the trumpet had sounded, [Refs 5th c.BC+]
__I.2 with implied reference to some later time, ἐ. or ἐπειδή, ={ἐξ οὗ}, from the time when, since, mostly with aorist, πολλὰ πλάγχθη, ἐ. ἔπερσε [Refs 8th c.BC+]; ἐπειδήτε παρέλαβον τὸν θρόνον, τοῦτο ἐφρόντιζον ever since I came to the throne, I had this in mind, [Refs 5th c.BC+]present (used in perfect sense) and perfect, ἐ. δὲ φροῦδός ἐστι στρατός since the army is gone, [Refs 5th c.BC+]; ἐπειδήτε ὑπὸ τῷ Πέρσῃ εἰσί, πεπόνθασι τοιόνδε ever since they have been, now that they are.., [Refs 5th c.BC+]
__II with Subj., ἄν being always added in Attic dialect Prose, and ἄν or κε generally in Poetry: ἐπειδή with ἄν becomes ἐπήν (so in Comedy texts, [Refs 5th c.BC+], Ionic dialect ἐπεάν [ἐπειδή κε, ἐπήν (once ἐπεὶ ἄν 8th c.BC: Ilias Homerus Epicus “Illiad” 6.412): ">Refs 8th c.BC+]
__II.1 referring to future time with future apodosis, τέκνα ἄξομεν.. ἐπὴν πτολίεθρον ἕλωμεν when we shall have taken the city, [Refs 8th c.BC+]; ταῦτ᾽, ἐπειδὰν περὶ τοῦ γένους εἴπω, τότ᾽ ἐρῶ I will speak of this, when I have spoken.., [Refs 8th c.BC+]; χρὴ δέ, ὅταν μὲν τιθῆσθε τοὺς νόμους,.. σκοπεῖν, ἐπειδὰν δὲ θῆσθε, φυλάττειν whenever you are enacting your laws,.. and after you have enacted them.., [Refs 4th c.BC+]
__II.2 of repeated action, with a present apodosis, whenever, when once, δαμνᾷ, ἐ. κε λίπῃ ὀστέα θυμός [Refs 8th c.BC+]; ἐπειδὰν ἡ ἐκφορὰ ᾖ.. ἄγουσι whenever the burial takes place they bring, [Refs 5th c.BC+]; ἐπειδὰν κρύψωσι γῇ.. λέγει when they have covered them with earth, [Refs]κε in Poets, ἐ. ἂρ βλέφαρ᾽ ἀμφικαλύψῃ [Refs 8th c.BC+]
__II.3 like [Refs 4th c.BC+] within ten days from the passing of the resolution, [Refs]
__III with Opt. (without ἄν):
__III.1 referring to future time, ἐπειδὴ πρὸς τὸ φῶς ἔλθοι, ὁρᾶν οὐδ᾽ ἂν ἓν δύνασθαι (i.e. οὐκ οἴει); after he had come into the light.., [ἐπειδή, 8th c.BC: Ilias Homerus Epicus “Illiad” 24.227, 8th c.BC: Odyssea Homerus Epicus “Odyssey” 2.105 (codices), etc. ">Refs 8th c.BC+]
__III.2 more frequently of repeated action, with a past apodosis, ἐ. ζεύξειεν.., δησάσκετο [Refs 8th c.BC+]
__III.3 in indirect speech after past tenses, representing a subjunctive in direct speech, αὐτὸς δὲ ἐπεὶ διαβαίης, ἀπιέναι ἔφησθα (the direct form being ἐπὴν διαβῶ) [Refs 5th c.BC+]; after optative in a final clause, ἐπορεύοντο, ὅπως ἐπειδὴ γένοιντο ἐπὶ τῷ ποταμῷ.. ἴοιεν [Refs 5th c.BC+]
__III.4 by assimilation to optative in principal clause, ἦ τ᾽ ἂν.. νῦν μὲν ἀνώγοιμι πτολεμίζειν.. ἐπὴν τεισαίμεθα λώβην [Refs 8th c.BC+]
__III.5 ἐπειδάν with optative is falsa lectio in some passages of early authors, as [Refs 5th c.BC+]: found in later Gr., [Refs 1st c.BC+]
__IV with Inf., only in indirect speech, ἐπειδὴ δὲ κατὰ σχολὴν σκέψασθαι, κόπτεσθαι (i.e. ἔφη) [Refs 5th c.BC+]
__V with other words:
__V.1 ἐ. τάχιστα as soon as, frequently separated by a word, ἐ. ἦλθε τάχιστα,.. ἀπέδοτο [Refs 5th c.BC+]
__V.1.b ἐ. τὰ πρῶτα [Refs 8th c.BC+]
__V.2 with emphatic Particles, ἐπεὶ ἄρα when then, in continuing a narrative, [Refs 8th c.BC+]; ἐπεὶ οὖν when then, in resuming a narrative, [Refs 5th c.BC+]
__B CAUSAL (ἐπειδή more frequently in this sense in early Prose: ἐπειδή whereas is used in preambles of decrees, [Refs]inasmuch as, NT.Luke.1.1), since, seeing that, frequently from [Refs 8th c.BC+]
__B.1 with Ind. (after both present and past tenses), ἐ. οὐδὲ ἔοικε [ἐπειδήπερ ἕσπετ᾽, ἐμπέδως μένοι 4th-5th c.BC: Aeschylus Tragicus “Agamemnon” 854 ">Refs 8th c.BC+]; frequently with past tenses with ἄν, ἐπεὶ οὔποτ᾽ ἂν στόλον ἐπλεύσατ᾽ ἄν [Refs 8th c.BC+]; οὐ γὰρ ἂν σθένοντά γε εἷλέν μ᾽· ἐπεὶ οὐδ᾽ ἂν ὧδ᾽ ἔχοντ᾽ (i.e. εἷλεν) [Refs 5th c.BC+]: especially in the sense, for otherwise.., [Refs 5th c.BC+]future, ἐξέστω δὲ μηδενὶ.. τεθῆναι.., ἐ. ἀποδώσει.. otherwise he shall pay.., [Refs] for teach me, [Refs 5th c.BC+]: with an interrogative, ἐ. πῶς ἂν καλέσεια; for how would you call him? [Refs 5th c.BC+]
__B.2 with Opt., ἐ. ἂν μάλα τοι σχεδὸν ἔλθοι [Refs 8th c.BC+]; so after past tenses on the principle of indirect speech, ἐπειδήπερ ἡγήσαιντο since (as they said) they believed, [Refs 5th c.BC+]
__B.3 with Inf. in indirect speech, ἐ. γιγνώσκειν γε αὐτά [Refs 5th c.BC+]
__B.4 in elliptical expressions, ἀδύνατός [εἰμι], ἐ. ἐβουλόμην ἂν οἷός τ᾽ εἶναι I am unable (and yet I am sorry), for I should like to have the power, [Refs 5th c.BC+]; so εἶμι· ἐ. καὶ ταῦτ᾽ ἂν ἴσως οὐκ ἀηδῶς σου ἤκουον [Refs]and yet, although, compare [Refs 4th c.BC+]; ἐ. ὅ γε ἀποθανὼν πελάτης τις ἦν ἐμός and yet (moreover) the murdered man was my own hired man, [Refs 5th c.BC+]
__B.4.b sometimes after a vocative, where 'listen' may be supplied, Ἕκτορ, ἐ. με κατ᾽ αἶσαν ἐνείκεσας [Refs 8th c.BC+]
__B.5 with other Particles, ἐ. ἄρα, ἐ. ἂρ δή since then, [Refs 8th c.BC+]; ἐ. γε (ἐπειδή.. γε [Refs 8th c.BC+] since indeed, [Refs 5th c.BC+]; ἐπειδή γε[Refs 5th c.BC+]; ἐ. ἦ since in truth, ἐ. ἦ πολὺ φέρτερόν ἐστι [Refs 8th c.BC+]; ἐπειδήπερ (ἐ... περ [Refs 8th c.BC+]; ἐπειδήπερ in Comedy texts and Prose, [Refs 5th c.BC+]; ἐ. τοι since surely, [Refs 8th c.BC+] sometimes begins a verse in [Refs 8th c.BC+]; sometimes coalesces by synizesis with οὐ, οὐδέ, etc., [Refs 5th c.BC+]

_{LSJ Scripture Refs: Luke.1.1}