The name Indomitable Spirit Korean in old Korean Hanja...

不屈 is the short form of a longer Chinese word and also a word used in Korean and Japanese to express the idea of being indomitable. It literally means “will not bend,” “will not crouch,” “will not yield,” “will not flinch,” or “will not submit.”

Note: Some will translate this as “indomitable spirit”; however, technically, there is no character to suggest the idea of “spirit” in this word.

See Also:  Tenacity | Fortitude | Strength | Undaunted

百折不屈 is a Korean proverb that means “indomitable spirit,” at least, that is the way it is commonly translated in martial arts circles (Taekwondo, Hapkido, etc.).

The literal translation is “[one] hundred [times] broken [still] don't succumb.”
Or more naturally translated, “Even if attacked/beaten one hundred times, still be undaunted/indomitable.”

Notes:
Some will say this is one long word rather than a proverb.
This is also a proverb/word in Chinese though rarely used in modern times.

廉耻精進忍耐遵守克己謙遜百折不屈 are the tenets of Tang Soo Do.

After some research, it appears this list was compiled in English based on Taekwondo tenets. We filled in a few of the words that did not have a corresponding Hanja or Hangul. If someone else has a better list with characters included, please contact me.

跆拳道精神禮義廉耻忍耐克己百折不屈 is General Choi's writing that is often called “The Tenets of Taekwon-do.”

The actual title would be translated as “Taekwondo Spirit” or “The Spirit of Taekwondo.” It was originally written in Korean Hanja (Chinese characters used in Korea for about 1600 years).