1. excessive confidence in one's abilities, judgment, or success; unwarranted belief that one will succeed or is right
Usage: uncountable; typically viewed as a negative trait

Examples

• His overconfidence in his driving skills led to a serious accident.
• The team's overconfidence before the championship game cost them the title.
• She warned against overconfidence when investing in the stock market.
• Overconfidence can prevent people from preparing adequately for challenges.
• The candidate's overconfidence made him unprepared for tough interview questions.
• Many startups fail due to the founder's overconfidence in their business model.
• Overconfidence bias causes people to overestimate their knowledge and abilities.