From Longman Dictionary of Contemporary Englishof course notof course not (also course not informal) spokenUNTRUE used to say very strongly that something is not true or correct He asked his father if it was true. ‘Of course not, ’ Jack said. ‘You don’t mind if I call her?’ ‘No, course not.’ → course
Examples from the Corpus
of course not• Of course not all women are traditional.• Of course not, you dummy.• Of course not, you were too young.• Cooley sees some of it in everyone, of course not the same amounts in every person.• I mean, no, of course not.• No, of course not, how could you?• No, of course not, it was just a feeling she liked, a tiny, private freedom.• "Are you serious about Sam?" "Of course not, we're just good friends."• Two serious actors, though of course not at their most serious here.• "Don't tell anyone else, will you?" "Of course not." 