| hard-boiled(adjective, hard, unfeeling, unsympathetic, hardened) |
| hardboiled(adjective, determined, serious, resolute, persistent) |
| hardened(adjective, hard, tough, unfeeling, unsympathetic) |
| hardhearted(adjective, hard, unfeeling, unsympathetic, hardened) |
| heartless(adjective, hard, unfeeling, unsympathetic, hardened) |
| impenetrable(adjective, hard, unfeeling, unsympathetic, prepared) |
| impious(adjective, hard, unfeeling, unsympathetic, prepared) |
| inaccessible(adjective, hard, unfeeling, unsympathetic, prepared) |
| indurated(adjective, hard, unfeeling, unsympathetic, hardened) |
| intent(adjective, serious, resolute, persistent, unwavering) |
| inured(adjective, hard, unfeeling, unsympathetic, hardened) |
| irreverent(adjective, hard, unfeeling, unsympathetic, prepared) |
| mean business(expression, adjective, serious, resolute, persistent) |
| obdurate(adjective, hard, unfeeling, unsympathetic, hardened) |
| obstinate(adjective, serious, resolute, persistent, unwavering) |
| obtuse(adjective, hard, unfeeling, unsympathetic, prepared) |
| on ice(expression, adjective, serious, resolute, persistent) |
| pat(adjective, serious, resolute, persistent, unwavering) |
| persevering(adjective, serious, resolute, persistent, unwavering) |
| persistent(adjective, serious, resolute, unwavering, gritty) |