ˈknow-it-all BrE AmE noun [countable] especially American English informal
someone who behaves as if they know everything – used to show disapproval SYN know-all British English
ˈknow-it-all BrE AmE noun [countable] especially American English informal
someone who behaves as if they know everything – used to show disapproval SYN know-all British English
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012