συνεπιμαρτυρέω
From LSJ
ἔνδον γὰρ ἁνὴρ ἄρτι τυγχάνει, κάρα στάζων ἱδρῶτι καὶ χέρας ξιφοκτόνους → yes, the man is now inside, his face and hands that have slaughtered with the sword dripping with sweat
English (LSJ)
A join in attesting, Arist.Mu.400a15, Thphr.CP6.16.6, Ep.Hebr.2.4; τινι with one, Plb.25.6.4, Aristeas191, Plu.2.542c, Gal.15.583, Ath.13.595e; add one's evidence, Plu.2.486c,539d. II Astrol., to be also configurate, of planets, Nech. ap. Vett.Val.279.3, Cat.Cod.Astr.2.187.