συναποθνῄσκω
From LSJ
Τούτῳ τῷ λόγῳ χρήσαιτο ἄν τις ἐπ' ἐκείνων τῶν ἀνθρώπων οἳ παραδόξως ἀλαζονεύονται, μηδὲ τὰ κοινὰ τοῖς ἀνθρώποις ἐπιτελεῖν δυνάμενοι → One would use this fable for those who give themselves unreasonable airs, but can't handle everyday life (Aesop 40)
French (Bailly abrégé)
mourir avec, τινι.
Étymologie: σύν, ἀποθνῄσκω.
English (Thayer)
2nd aorist συναπεθανον; to die together; with the dative of the person to die with one (Herodotus down): ὑμᾶς ἐμοί, that ye may die together with me, i. e. that my love to you may not leave me even were I appointed to die, τῷ Χριστο (cf. Winer's Grammar, 143 (136)), to meet death as Christ did for the cause of God, 2 Timothy 2:11.