2) the coming, arrival, advent
2a) the future visible return from heaven of Jesus, to raise the dead, hold the last judgment, and set up formally and gloriously the kingdom of God
Part of Speech: noun feminine
Citing in TDNT: 5:858, 791
From the present participle of G3918; a being near, that is, advent (often, return; specifically of Christ to punish Jerusalem, or finally the wicked); (by implication) physical aspect: - coming, presence.
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 παρουσία; click on the second column to search for that grammatical form of the root παρουσία; click on the third column to search for that word and grammatical form; click on the total to search for the root παρουσία.