cocksure
🇺🇸
/ˌkɑːkˈʃʊr/
🇬🇧
/ˌkɒkˈʃʊə(r)/
overconfident in a way that is annoying to others
The new employee was so cocksure that he didn't listen to anyone's advice.
新しい社員は非常に自信に満ちており、誰のアドバイスも聞かなかった。