πάνδεινος
From LSJ
οἱ τοῖς πέλας ἐπιβουλεύοντες, λανθάνουσι πολλὰκις ὑφ' ἑτέρων τοῦτ' αὐτὸ πάσχοντες → when people plot against their neighbours, they fall victim to the same sort of plot themselves
English (LSJ)
ον,
A all-dreadful, terrible, πάνδεινον ἡ ἀδικία Pl.R.610d, cf. 605c; πρᾶγμα D.54.33, cf. Men. Sam.212, Ruf.Fr.69; πάνδεινα πεπονθέναι Luc.Prom.8; πάνδεινόν [ἐστι] it is outrageous, D.23.79, cf. PTeb.27.34 (ii B. C.), Phld.Ir.p.86 W. II very able, c. inf., Pl. Plt.290b; ironically, D.19.120.