| certain(adjective, firm, determined, usual, regular) |
| cold fish(expression, adjective, mean, hard, stubborn) |
| concluded(adjective, firm, determined, usual, regular) |
| confirmed(adjective, firm, determined, usual, regular) |
| conscientious(adjective, careful, thorough, dogged, meticulous) |
| constant(adjective, persistent, pitiless, unyielding, endless) |
| continual(adjective, persistent, constant, pitiless, unyielding) |
| continuous(adjective, persistent, constant, pitiless, unyielding) |
| customary(adjective, firm, determined, usual, regular) |
| dead set on(expression, adjective, idiom, firm, determined) |
| decided(adjective, firm, determined, usual, regular) |
| decisive(adjective, firm, determined, usual, regular) |
| definite(adjective, firm, determined, usual, regular) |
| endless(adjective, persistent, constant, pitiless, unyielding) |
| entrenched(adjective, firm, determined, usual, regular) |
| hard(adjective, mean, tough, harsh, inflexible) |
| hard-boiled(adjective, mean, hard, tough, harsh) |
| hard-headed(adjective, persistent, constant, pitiless, unyielding) |
| hard-hearted(adjective, mean, hard, tough, harsh) |
| harsh(adjective, mean, hard, tough, inflexible) |