φρουρέω, φρούρω: imperfect ἐφρουρουν; future φρουρήσω; passive, present participle φρουρουμενος; imperfect ἐφρουρουμην; (φρουρός, contracted from πρωρος from πρωράω to see before, foresee); from Aeschylus and Herodotus down;

1. to guard, protect by a military guard, either in order to prevent hostile invasion, or to keep the inhabitants of a besieged city from flight; (often so from Thucydides down): τήν πόλιν, i. e. not he surrounded the city with soldiers, but by posting sentries he kept the gates guarded, 2Co 11:32 (R. V. guarded), cf. Act 9:24.

2. metaphorically: τινα, passive, ὑπό νόμον, under the control of the Mosaic law, that we might not escape from its power, with συγκεκλεισμένοι (συν῾γ᾿κλειόμενοι L T Tr WH) added, Gal 3:23 (R. V. kept in ward; cf. Plutarch, de defect. orac. § 29; Wis 17:15); to protect by guarding (Sophocles O. R. 1479), to keep: τάς καρδίας ἐν Χριστῷ, i. e. in close connection with Christ, Php 4:7; τινα εἰς τί, by watching and guarding to preserve one for the attainment of something (R. V. guarded unto etc.), passive, 1Pe 1:5.