NITWIT Meaning of NITWIT in English nit ‧ wit /ˈnɪt-wɪt/ BrE AmE noun [countable] informal [ Date: 1900-2000 ; Origin: Probably from German dialect nit 'not' + English wit ] a silly person Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012