1) to pick out, choose, to pick or choose out for one's self
1a) choosing one out of many, i.e. Jesus choosing his disciples
1b) choosing one for an office
1c) of God choosing whom he judged fit to receive his favours and separated from the rest of mankind to be peculiarly his own and to be attended continually by his gracious oversight
1c1) i.e. the Israelites
1d) of God the Father choosing Christians, as those whom he set apart from the irreligious multitude as dear unto himself, and whom he has rendered, through faith in Christ, citizens in the Messianic kingdom: (Jam 2:5) so that the ground of the choice lies in Christ and his merits only
Part of Speech: verb
Citing in TDNT: 4:144, 505
Middle voice from G1537 and G3004 (in its primary sense); to select: - make choice, choose (out), chosen.
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 ἐκλέγομαι; click on the second column to search for that grammatical form of the root ἐκλέγομαι; click on the third column to search for that word and grammatical form; click on the total to search for the root ἐκλέγομαι.