不ふ倒とう

noun which may take the genitive case particle 'no'

unbeatable; indestructible; impossible to knock over

Literally 'not falling'; used attributively in compounds like 不倒の精神 (indomitable spirit) or 不倒の城 (impregnable castle). Not a standalone adjective in modern Japanese.

• 彼かれは不ふ倒とうの精せい神しんで難なん局きょくを乗のり切きった。

  He overcame the crisis with an indomitable spirit.

• その城しろは不ふ倒とうの要よう塞さいとして知しられていた。

  The castle was known as an impregnable fortress.