1) a doing, a mode of acting, a deal, a transaction
1a) the doings of the apostles
1b) in a bad sense, wicked deed, crime, wicked doings (our practices, i.e. trickery)
2) a thing to be done, business
Part of Speech: noun feminine
Citing in TDNT: 6:642, 927
From G4238; practice, that is, (concretely) an act; by extension a function: - deed, office, work.
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 πρᾶξις; click on the second column to search for that grammatical form of the root πρᾶξις; click on the third column to search for that word and grammatical form; click on the total to search for the root πρᾶξις.