1) to place around one
2) to stand around
2a) to turn one's self about for the purpose of avoiding something
2b) to avoid, shun
Part of Speech: verb
From G4012 and G2476; to stand all around, that is, (near) to be a bystander, or (aloof) to keep away from: - avoid, shun, stand by (round about).
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 περιΐστημι; click on the second column to search for that grammatical form of the root περιΐστημι; click on the third column to search for that word and grammatical form; click on the total to search for the root περιΐστημι.