προομνύναι

From LSJ

κακῆς ἀπ΄ἀρχῆς γίγνεται τέλος κακόν. → from a bad beginning comes a bad end (Euripides' Aeolus fr. 32)

Source

Greek > English (Woodhouse Verbs Reversed)

(see also: προόμνυμι) swear beforehand