βεβαιοῦσθαι
From LSJ
ἀσκεῖν περὶ τὰ νοσήματα δύο, ὠφελεῖν ἢ μὴ βλάπτειν → strive, with regard to diseases, for two things — to do good, or to do no harm | as to diseases, make a habit of two things — to help, or at least, to do no harm
Greek > English (Woodhouse Verbs Reversed)
(see also βεβαιόω): secure for oneself
