ἀντιπρεσβεύεσθαι

From LSJ

τὸ ὅλον τόδε ποσαπλάσιον τοῦδε γίγνεται → how many times greater is this whole sum than that one

Source

Greek > English (Woodhouse Verbs Reversed)

(see also: ἀντιπρεσβεύομαι) send a counter-embassy

Lexicon Thucydideum

legatos vicissim mittere, to send envoys in turn, 6.75.3.