Definition of "indomitable"

Personal courage and an indomitable self-confidence were the chief, indeed the only, qualities which sprang to light in General Feversham.

1902, A. E. W. Mason, chapter 1, in The Four Feathers

But he was a youth of indomitable spirit, strong and agile as a wild cat.

1910, William Henry Hudson, chapter 7, in A Shepherd's Life

Nobody came on to the movie camera—wrapped it in a bear hug and wrestled it to submission—like Betty Hutton. They called this 40s singer-actress "the Blitzkrieg blond" . . [S]he was indomitable, unstoppable.

2007 March 31, Richard Corliss, “When Betty Got Frank”, in Time‎, archived from the original on 2010-12-03

And even though the rest of the auto industry, seeing Tesla’s growth, jumped on the electric vehicle bandwagon, Tesla has maintained an indomitable lead.

2022 April 28, Farhad Manjoo, “Is Elon Musk Really That Bad?”, in The New York Times‎