ἐμφρουρεῖν
From LSJ
Ἐκ τῶν πόνων τοι τἀγάθ' αὔξεται βροτοῖς → Crescunt labore cuncta bona mortalibus → Das Gute wächst den Sterblichen aus ihrem Müh'n
Greek > English (Woodhouse Verbs Reversed)
(see also: ἐμφρουρῶ, ἐμφρουρέω) be on guard
Lexicon Thucydideum
custodias agere in loco, to keep watch at a place, 4.110.1, 8.60.1.