1) an accuser
1a) a name given to the devil by the rabbis
Part of Speech: noun masculine
Citing in TDNT: 3:636, 422
From G2596 and G58; against one in the assembly, that is, a complainant at law; specifically Satan: - accuser.
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 κατήγωρ; click on the second column to search for that grammatical form of the root κατήγωρ; click on the third column to search for that word and grammatical form; click on the total to search for the root κατήγωρ.