δεῖν (dein)

δεῖν is an Ancient Greek form of δεῖ, meaning “it is necessary, one must”. It is the present active infinitive.

Found 2,205 times in the Ancient Greek texts on Socratos.

Where it is used

Apollonius Rhodius, Argonautica 3.557: δείνʼ ἐπαλαστήσας μεγάλῃ ὀπί, φώνησέν τε·

Thucydides, History of the Peloponnesian War 3.43.2: καθέστηκε δὲ τἀγαθὰ ἀπὸ τοῦ εὐθέος λεγόμενα μηδὲν ἀνυποπτότερα εἶναι τῶν κακῶν, ὥστε δεῖν ὁμοίως τόν τε τὰ δεινότατα βουλόμενον πεῖσαι ἀπάτῃ προσάγεσθαι τὸ πλῆθος καὶ τὸν τὰ ἀμείνω λέγοντα ψευσάμενον πιστὸν γενέσθαι.

Euripides, Cyclops 375: ὦ Ζεῦ, τί λέξω, δείν’ ἰδὼν ἄντρων ἔσω

All forms of δεῖ (conjugation table)

Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Liddell-Scott-Jones, A Greek-English Lexicon (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.