epeidē

ἐπεί,
conjunction, both temporal and causal; also ἐπειδή, ἐπείτε. 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, ἐπεί 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+; ἐπείτε 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+; ἐπείτε 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: ἐπεί with ἄν becomes ἐπήν (so in Comedy texts, Refs 5th c.BC+, Ionic dialect ἐπεάν 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, Refsκε 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.., 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 (ἐπεί more frequently in this sense in early Prose: ἐπειδή whereas is used in preambles of decrees, Refsinasmuch 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 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, ἐπείπερ 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 Refsand 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 (ἐπεί.. γε Refs 8th c.BC+ since indeed, Refs 5th c.BC+; ἐπειδή γεRefs 5th c.BC+; ἐ. ἦ since in truth, ἐ. ἦ πολὺ φέρτερόν ἐστι Refs 8th c.BC+; ἐπείπερ (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+

H. G. Liddell, R. Scott, H. S. Jones, A Greek-English Lexicon (9th ed., 1925–1940) — digitised by the Perseus Digital Library and corrected and expanded by Tyndale House, Cambridge, via STEPBible-Data's TFLSJ table, CC BY 4.0. Covers all of Greek literature, not just the Bible.