1) to be mad, to rave
1a) of one who so speaks that he seems not to be in his right mind
Part of Speech: verb
Citing in TDNT: 4:360, 548
Middle voice from a primary word μάω maô (to long for; through the idea of insensate craving); to rave as a "maniac": - be beside self (mad).
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 μαίνομαι; click on the second column to search for that grammatical form of the root μαίνομαι; click on the third column to search for that word and grammatical form; click on the total to search for the root μαίνομαι.