ἀντᾴδω
From LSJ
Ζῆν οὐκ ἄξιος, ὅτῳ μηδὲ εἷς ἐστι χρηστὸς φίλος → Life is not worth living if you do not have at least one friend.
English (LSJ)
A sing in answer, esp. of the partridge, answer when another calls, ἀ. ὡς μαχούμενος Arist.HA614a11, cf. Mir.845b25, Ael.NA4.16; ἀ. Μούσαις Luc.Pisc.6; τοῖς φθεγγομένοις Plu.2.794c; cry out at one, ἐγὼ δ', ἢν τοῦτο δρᾷς, ἀντᾴσομαι Ar.Ec.887:—Pass., στροφῇ ἀντᾳσθῆναι Poll.4.112.