always determined and energetic in attempting to achieve something and never willing to admit defeat
发音
例句
1. His indefatigable spirit helped him to cope with his illness. 他不屈不挠的精神帮助他对抗病魔。 2. He was indefatigable in his lectures on the aesthetics of love. 在讲授关于爱情的美学时,他是不知疲倦的。