triumphalist

/traɪˈʌmfəlɪst/
adjective
  1. Showing or feeling great pride and satisfaction about a victory or success, especially in a way that seems arrogant or overly confident.
    • Her triumphalist speech made it sound like she had single-handedly solved the problem.
    • The team's triumphalist celebration after winning the championship annoyed the losing fans.
    • Some critics found the movie's ending too triumphalist, as if it ignored the real struggles.
Antonyms
noun
  1. A person who expresses or feels great pride and satisfaction about a victory or success, often in an arrogant or overly confident way.
    • He was a triumphalist who never missed a chance to remind others of his team's record.
    • The politician was accused of being a triumphalist, always boasting about his achievements.
    • As a triumphalist, she could not understand why others were not as excited about the project's success.