dar las gracias
From LSJ
ἐς δὲ τὰ ἔσχατα νουσήματα αἱ ἔσχαται θεραπεῖαι ἐς ἀκριβείην, κράτισται → for extreme diseases, extreme methods of cure, as to restriction, are most suitable (Corpus Hippocraticum, Aphorisms 1.6.2)
Spanish > Greek
ἀμείβω, χάριν γνῶναι (see in γιγνώσκω), ἀποχαριστέω