| insubordinate(adjective, persistent, obstinate, insistent, dogged) |
| insurgent(adjective, persistent, obstinate, insistent, dogged) |
| intransigent(severe, determined, hostile, stiff, inflexible) |
| inveterate(adjective, persistent, obstinate, insistent, dogged) |
| invincible(adjective, persistent, obstinate, insistent, dogged) |
| iron(adjective, persistent, obstinate, insistent, dogged) |
| irreconcilable(adjective, hostile, conflicting) |
| locked(determined, obstinate, stubborn, willful) |
| locked in(expression, tough, severe, difficult, stiff) |
| mortified(adjective, strong, hard, tough, severe) |
| mulish(adjective, strong, hard, tough, severe) |
| mutinous(adjective, persistent, obstinate, insistent, dogged) |
| obsessive(adjective, persistent, obstinate, insistent, dogged) |
| pat(tough, difficult, wild, awkward, obstinate) |
| persistent(adjective, obstinate, insistent, dogged) |
| pertinacious(tough, firm, difficult, determined, awkward) |
| perverse(tough, difficult, awkward, obstinate, stubborn) |
| pigheaded(tough, firm, difficult, determined, awkward) |
| resolute(tough, firm, difficult, fixed, rigid) |
| resolved(adjective, persistent, obstinate, insistent, dogged) |