1. 〔生まれ付きの性質・性根〕one's innate character;〔根性〕spirit,《口》 fight,《口》 guts;〔意志力〕willpower
    • 彼は土性骨がない
    • He has no backbone./He hasn't got any guts.
    • あいつの土性骨をたたき直してやる
    • I'll beat the faintheartedness out of him.