σύμμαρτυς
From LSJ
τὸ κατὰ τὴν τῆς αὑτοῦ ψυχῆς ἐπίταξιν τὰ γιγνόμενα γίγνεσθαι, μάλιστα μὲν ἅπαντα, εἰ δὲ μή, τά γε ἀνθρώπινα → the desire that, if possible, everything,—or failing that, all that is humanly possible—should happen in accordance with the demands of one's own heart
English (LSJ)
ῠρος, ὁ, ἡ,
A fellow-witness, joint-witness, S.Ant.846 (lyr., pl.), Pl.Ep.311e; τινος of or to a thing, Id.Phlb.12b, cf. CIG3194 (Smyrna).