ματαιόομαι
From LSJ
οὐκ ἔστι λέουσι καὶ ἀνδράσιν ὅρκια πιστά → there are no pacts between lions and men, between lions and men there are no oaths of faith, there can be no covenants between men and lions
Greek (Liddell-Scott)
μᾰταιόομαι: Παθ., ἀπατῶμαι, Μελέτ. ἐν. Ἀνεκ. Ὀξων. τ. 3. σ. 5· μεματαίωταί σοι, ἔχεις πράξει ἀνοήτως, Ἑβδ. (Α΄ Σαμ. ΙΓ΄, 13)· ― οὐσιαστ. ματαίωσις, εως, ἡ, Ἀθανάσ. τ. 1, σ. 1041Α.