1) adoption, adoption as sons
1a) that relationship which God was pleased to establish between himself and the Israelites in preference to all other nations
1b) the nature and condition of the true disciples in Christ, who by receiving the Spirit of God into their souls become sons of God
1c) the blessed state looked for in the future life after the visible return of Christ from heaven
Part of Speech: noun feminine
Citing in TDNT: 8:397, 1206
From a presumed compound of G5207 and a derivative of G5087; the placing as a son, that is, adoption (figuratively Christian sonship in respect to God): - adoption (of children, of sons).
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 υἱοθεσία; click on the second column to search for that grammatical form of the root υἱοθεσία; click on the third column to search for that word and grammatical form; click on the total to search for the root υἱοθεσία.