To hold one's chest out; to act proudly or confidently, often with an air of self-assurance.
合格発表で自分の番号を見つけて、彼は胸を張って教室を出て行った。
After finding his number on the exam results, he walked out of the classroom with his chest held high.
失敗しても胸を張って前に進めば、次に繋がることもある。
Even if you fail, moving forward with your head held high can lead to future opportunities.
彼女は自分の仕事に誇りを持っており、胸を張って成果を報告した。
She is proud of her work and reported her results with confidence.
胸を張っていいよ。君はよく頑張った。
Be proud — you did a great job.