Lexical Definition

‎δεῖ‎ deî (die) be necessary G:V
3rd person singular active present of ‎δέω‎

behoved, be meet, must (needs), (be) need(-ful), ought, should.

Usage: 11 forms in 132 verses
Form Translated As     In Verse(s)
ἔδει it was being necessary Acts.17.3
it was fitting Luke.15.32
it was necessary Matt.18.33 • Matt.23.23 • Matt.25.27 • Acts.24.19 • Acts.27.21 • 2Cor.2.3
it was necessary for Luke.11.42 • Luke.22.7 • Luke.24.26 • Luke.24.46 • John.4.4 • Acts.1.16 • Heb.9.26
she was being able Luke.13.16
was fitting Rom.1.27
δεῖν needing Luke.18.1 • Acts.25.24 • Acts.26.9
δεῖ is necessary Acts.16.30
it behooves Matt.17.10 • Mark.9.11 • Mark.13.10 • Luke.2.49 • Luke.4.43 • Luke.12.12 • Luke.13.14 • Luke.13.33 • Luke.17.25 • Luke.19.5 • Luke.21.9 • Luke.22.37 • Luke.24.7 • Luke.24.44 • John.3.14 • John.3.30 • John.4.24 • John.9.4 • John.10.16 • John.12.34 • Acts.1.21 • Acts.3.21 • Acts.4.12 • Acts.9.6 • Acts.9.16 • Acts.10.6 • Acts.14.22 • Acts.19.21 • Acts.20.35 • Acts.23.11 • Acts.25.10 • Acts.27.24 • Acts.27.26 • Rom.8.26 • Rom.12.3 • 1Cor.11.19 • 1Cor.15.25 • 1Cor.15.53 • 2Cor.5.10 • 2Cor.11.30 • 2Cor.12.1 • Eph.6.20 • Col.4.4 • Col.4.6 • 1Thess.4.1 • 2Thess.3.7 • 1Tim.3.2 • 1Tim.3.7 • 1Tim.3.15 • 2Tim.2.24 • Titus.1.7 • Heb.2.1 • Heb.11.6 • Rev.1.1 • Rev.4.1 • Rev.17.10
it is necessary Matt.24.6 • John.4.20 • Acts.5.29 • Acts.15.5 • 1Cor.8.2 • 2Tim.2.6 • Titus.1.11 • Rev.10.11 • Rev.11.5
it is necessary for Matt.16.21 • Mark.8.31 • Luke.9.22 • John.3.7 • John.20.9 • Rev.13.10 • Rev.20.3
it must Mark.13.7
it must be Matt.26.54
it should Mark.13.14
must Rev.22.6
necessary Acts.18.21
ought Titus.1.11 • 2Pet.3.11
should Acts.21.22
δεόντα necessary LXX.1Kgs.4.22
δει a must LXX.Prov.23.2
he must not LXX.Lev.4.2
it is necessary LXX.Isa.50.4
must LXX.Lev.5.17 • LXX.Ruth.4.5 • LXX.2Kgs.4.14 • LXX.Esth.1.15 • LXX.Prov.22.29 • LXX.Isa.30.29 • LXX.Dan.2.28 • LXX.Dan.2.29 • LXX.Dan.2.29 • LXX.Dan.2.45
must not LXX.Job.15.3 • LXX.Dan.6.15
δεήσει it shall behoove LXX.Josh.18.4
δέῃ it shall be necessary for Matt.26.35
it shall be needful Mark.14.31
δέοντα being proper 1Tim.5.13
necessary LXX.Exod.16.22 • LXX.Exod.21.10 • LXX.Prov.30.8 • LXX.Dan.11.26
δέον being necessary 1Pet.1.6
necessary Acts.19.36
δέη it is necessary LXX.Esth.4.16
έδει he must LXX.2Sam.4.10
must not LXX.Job.19.4 • LXX.Ezek.13.19 • LXX.Ezek.13.19

Abbott-Smith

δεῖ impersonal (δέω), [in LXX chiefly for infin. with לְ ;]
one must, it is necessary: c. inf., Mt 26:54, Mk 13:7, Ac 5:29, al.; c. acc. et inf., Mt 16:21, Mk 8:31, Jo 3:7, Ac 25:10, al.; with ellipse of acc., Mt 23:23; of acc., and inf., Mk 13:14, Ro 1:27 8:26; οὐ (μὴ) δεῖ (non licet), ought not, must not: Ac 25:24, II Ti 2:24; impf., ἔδει, of necessity or obligation in past time regarding a past event (Bl., § 63, 4), Mt 18:33, Lk 15:32, Jo 4:4, Ac 27:21, al.; periphr., δέον ἐστίν (as in Attic, χρεών ἐστι = χρή, v.s. δέον), Ac 19:36; id., with ellipse of ἐστίν, I Pe 1:6 τὰ μὴ δέοντα (= ἃ οὐ δεῖ I Ti 5:13.
SYN.: ὀφείλει, expressing moral obligation, as distinct from δεῖ, denoting logical necessity and χρή, a need which results from the fitness of things (v. Tr., Syn., § cvii, 10; Westc. on He 2:1, I Jo 2:6; Hort on Ja 3:10).

Abbott-Smith References

Book Refs
Matthew 16:21 · 18:33 · 23:23 · 26:54
Mark 8:31 · 13:7 · 13:14
Luke 15:32
John 3:7 · 4:4
Acts 5:29 · 19:36 · 25:10 · 25:24 · 27:21
Romans 1:27 · 8:26
1 Timothy 5:13
2 Timothy 2:24
Hebrews 2:1
James 3:10
1 Peter 1:6
1 John 2:6

Liddell-Scott-Jones

δεῖ:

subjunctive δέη, sometimes contraction δῆ (in codices of Comedy texts, as [Refs 5th c.BC+]; ὁπόσου κα δῆ [Refs 5th c.BC+]; infinitive δεῖ; participle δέον (see. infr. IV): imperfect ἔδει, Ionic dialect ἔδεε: future δεήσει [Refs 5th c.BC+]: aorist I ἐδέησε [Refs 5th c.BC+] —Impers. from δέω (A), there is need (the sense of moral obligation, properly belonging to χρή, is later, [Refs 5th c.BC+]

__I c.accusative person et infinitive, it is needful for one to do, one must, once in [δεῖ πολεμιζέμεναι.. Ἀργείους">Refs 8th c.BC+] why need the Argives fight? [Refs 8th c.BC+]: with nominative of the pronoun, ἡγούμην.. δεῖν.. μεγαλοψυχότερος φαίνεσθαι [δεῖ σ᾽ ὅπως δείξεις, ={δεῖ σε δεῖξαι}, 5th c.BC: Sophocles Tragicus “Ajax” 556, compare “Ph.” 54; δεῖ σ᾽ ὅπως μηδὲν διοίσεις 5th c.BC: Cratinus Comicus 108; (the full \_construction\_ in 5th c.BC: Sophocles Tragicus “Philoctetes” 77 τοῦτο δεῖ σοφισθῆναι.. ὅπως γενήσῃ)">Refs 5th c.BC+]: rarely with dative person, there is need of.. for.., θεοῖσι προσβαλεῖν χθονὶ ἄλλην δεήσει γαῖαν [δεῖ (i.e. ἡμᾶς) 5th c.BC: Herodotus Historicus 1.8, compare 4th-5th c.BC: Aeschylus Tragicus “Agamemnon” 567, “Eu.” 826, etc. ">Refs 5th c.BC+]
__I.2 with accusative of things et infinitive, δεῖ τι γενέσθαι [Refs 5th c.BC+]; also ἐπεὶ δέ οἱ ἔδεε κακῶς γενέσθαι since it was fated for him.., since he was doomed.., [Refs 5th c.BC+]; for οἴομαι δεῖν, see at {οἴομαι}.
__I.3 absolutely with infinitive understood, μὴ πεῖθ᾽ ἃ μὴ δεῖ (i.e. πείθειν) [Refs 5th c.BC+]; εἴ τι δέοι, ἤν τι δέῃ (i.e. γενέσθαι), [Refs 5th c.BC+]; κἂν δέῃ (i.e. τροχάζειν), τροχάζῶ [Refs 6th c.BC+]
__II with genitive of things, there is need of, frequently with negative, οὐδὲν ἂν δέοι πολλοῦ ἀργυρίου [δεῖ τῆς ἀρετῆ; 4th c.BC: Aristoteles Philosophus “Politica” 1309b10 ">Refs 5th c.BC+]; sometimes with infinitive added, μακροῦ λόγου δεῖ ταῦτ᾽ ἐπεξελθεῖν [Refs 4th c.BC+]
__II.b frequently in phrases, πολλοῦ δεῖ there wants much, far from it, ὀλίγου δεῖ there wants little, all but; in full with infinitive, πολλοῦ δεῖ οὕτως ἔχειν [δεῖ, πολλοῦ γε καὶ δεῖ 5th-6th c.BC: Aristophanes Comicus “Acharnenses” 543, 4th c.BC: Demosthenes Orator 18.300, 21.71 ">Refs 5th c.BC+]; τοῦ πλεῦνος αἰεὶ ἔδεε there was always further to travel, [δεῖ 2nd c.AD: Lucianus Sophista “Merc.Cond.” 13: also ὀλίγου δεῖν">Refs 5th c.BC+] absolutely, in same sense, [δεῖν 4th c.BC: Demosthenes Orator 27.29. ">Refs 5th c.BC+]
__II.2 with dative person added, δεῖ μοί τινος [Refs 5th c.BC+]
__II.3 with accusative person added, αὐτὸν γάρ σε δεῖ προμηθέως [Refs 5th c.BC+]
__II.4 rarely with Subj. in nominative, δεῖ μοί τι something is needful to me, ἓν δεῖ μόνον μοι [δεῖ, ὑπειληφέναι.. 4th c.BC: Demosthenes Orator 10.15. ">Refs 5th c.BC+]
__III middle, δεῖται there is need, with genitive, δεῖταί σοι τῆς αὐτῆς ἐρωτήσεως [δεῖσθαι στρατηγοῦ νομίζων 1st-2nd c.AD: Plutarchus Biographus et Philosophus “Pelopidas” 26 ">Refs 5th c.BC+]: with infinitive, ὥστε βραχἔ ἐμοὶ δεῖσθαι φράσαι [δεῖται 3rd c.BC: Herodas Mimographus 6.41. ">Refs 5th c.BC+]
__IV neuter participle δέον (δεῖν is uncertain in [Refs 5th c.BC+]: absolutely, it being needful or fitting, [Refs 5th c.BC+]; οὐκ ἀπήντα, δέον, he did not appear in court, though he ought to have done so, [Refs 4th c.BC+]: with infinitive, [Refs 5th c.BC+]; οὐδὲν δέον there being no need, [Refs 5th c.BC+]: future ὡς αὐτίκα δεῆσον διώκειν [Refs 5th c.BC+]: aorist δεῆσαν [Refs 2nd c.BC+] with accusative infinitive, [Refs 1st c.AD+]
__IV.2 substantive δέον, τό (see entry vocative).