that makes somebody believe that something is true a convincing argument/explanation/case She sounded very convincing to me (= I believed what she said). a convincing victory/win (= an easy one) opposite unconvincingExtra examples He was far from convincing as a leader. I found his argument pretty convincing. She produced a convincing enough performance as the wronged wife. A long, complicated excuse always sounds less convincing. Is there convincing evidence that the vaccine is effective? She sounded very convincing to me. This explanation is not entirely convincing.