1) to guard, protect by a military guard, either to prevent hostile invasion, or to keep the inhabitants of a besieged city from flight
2a) under the control of the Mosaic law, that he might not escape from its power
2b) to protect by guarding, to keep
2c) by watching and guarding to preserve one for the attainment of something
Part of Speech: verb
From a compound of G4253 and G3708; to be a watcher in advance, that is, to mount guard as a sentinel (post spies at gates); figuratively to hem in, protect: - keep (with a garrison). Compare G5083.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root φρουρέω; click on the second column to search for that grammatical form of the root φρουρέω; click on the third column to search for that word and grammatical form; click on the total to search for the root φρουρέω.