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δεινόν

Ὁ δ' ἀνεξέταστος βίος οὐ βιωτὸς ἀνθρώπῳ -> The unexamined life is not worth living
Plato, Apology of Socrates 38a

Russian (Dvoretsky)

δεινόν:
I adv. страшно, грозно (ἀϋαι, δέρκεσθαι Hom.).
II τό
1) Aesch. = δεῖμα 1 и 2;
2) возмущение, негодование Her.