| case-hardened |
| certain(adjective, firm, determined, usual, regular) |
| close-minded(adjective, inflexible) |
| concluded(adjective, firm, determined, usual, regular) |
| confirmed(adjective, firm, determined, usual, regular) |
| cross-grained |
| customary(adjective, firm, determined, usual, regular) |
| dead set on(expression, adjective, idiom, determined, usual) |
| decided(adjective, firm, determined, usual, regular) |
| decisive(adjective, firm, determined, usual, regular) |
| definite(adjective, firm, determined, usual, unreasonable) |
| dense(adjective, informal, stubborn) |
| difficult(adjective, tough, awkward, obstinate, stubborn) |
| dour |
| entrenched(adjective, firm, determined, usual, regular) |
| fanatic |
| fanatical |
| forward(adjective, stubborn) |
| grim(adjective, determined, resolute, uncompromising, unshakeable) |
| hang tough(expression, tough, sharp, difficult, awkward) |