| unfaltering(adjective, strong, firm, energetic, determined) |
| unshakable(adjective, tough, firm, determined, resolute) |
| bigoted(adjective, determined, resolute, obstinate, uncompromising) |
| contrary(adjective, difficult, determined, awkward, resolute) |
| dour |
| fixed(adjective, tough, firm, determined, resolute) |
| immovable(adjective, difficult, determined, resolute, obstinate) |
| self-willed(adjective, tough, firm, difficult, determined) |
| set(adjective, determined, resolute, obstinate, uncompromising) |
| strong-willed |
| unbending(adjective, tough, determined, resolute, obstinate) |
| unflagging(adjective, strong, firm, energetic, determined) |
| unswerving(adjective, strong, tough, firm, determined) |
| bull-headed(adjective, determined, resolute, obstinate, stubborn) |
| importunate(adjective, demanding, insistent) |
| industrious(adjective, perseverance) |
| inexorable(adjective, tough, determined, resolute, obstinate) |
| pat(adjective, difficult, determined, resolute, obstinate) |
| sedulous |
| staunch(adjective, strong, tough, firm, determined) |