1.
willpower; guts; determination
Strong mental fortitude and perseverance. The ability to push through difficulties without giving up.
2.
temperament; nature; disposition
A person's fundamental character or nature, often used in a negative sense to describe an unpleasant disposition.
Sense 1 is positive, praising perseverance and fighting spirit. Common collocations: 根性がある (to have guts), 根性で頑張る (to persevere through willpower). Sense 2 is negative, describing someone's unpleasant character. Common collocations: 根性が悪い (bad-natured), 根性が曲がっている (twisted nature), 根性が腐っている (rotten character). The compound 根性論 refers to the belief that willpower alone can overcome any challenge.
Related Words
Synonym:
度胸 (nerve, boldness)
Related:
気概 (spirit)
Compare:
けなげさ (admirable courage)
Compare:
闘争心 (fighting spirit)
Compare:
気骨 (backbone)
Compare:
勝負心 (fighting spirit)
Compare:
負けん気 (competitive spirit)