| doggedness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| firmness |
| grimness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| hardheartedness(ruthlessness, pitilessness, mercilessness) |
| impenitence |
| imperviousness(noun, implacability) |
| implacability(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| implacableness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| incompliance(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| incompliancy(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| indomitability(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| induration |
| inexorability(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| inexorableness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| inflexibleness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| intransigency(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| mercilessness(ruthlessness, pitilessness) |
| mulishness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| obdurateness(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |
| pertinacity(obstinacy, stubbornness, inflexibility, ruthlessness, pitilessness) |