1) once, at once
1a) all at once
1b) once for all
Part of Speech: adverb
Citing in TDNT: 1:383, 64
From G1909 and G530; upon one occasion (only): - (at) once (for all).
|b once and for all||60.68|
|c at the same time||67.34|
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 ἐφάπαξ; click on the second column to search for that grammatical form of the root ἐφάπαξ; click on the third column to search for that word and grammatical form; click on the total to search for the root ἐφάπαξ.