| taut(adjective, strong, secure, substantial, stable) |
| tireless |
| tranquil(adjective, calm, cool, steady, unaffected) |
| unadaptable(adjective, hard, rigid, inflexible, strict) |
| unaffected(adjective, calm, cool, steady, detached) |
| uncooperative(adjective, mean, hard, difficult, wild) |
| unemotional(adjective, mean, cool, detached, blank) |
| unfeeling(adjective, mean, hard, cool, detached) |
| unflagging |
| unflappable(adjective, calm, cool, firm, usual) |
| unforgiving(adjective, determined, resolute, uncompromising, unshakeable) |
| unimpassioned(adjective, cool, detached, blank, sober) |
| unmanageable(adjective, tough, difficult, determined, fixed) |
| unmodifiable(adjective, fixed, stubborn) |
| unpliable(tough, difficult, obstinate, stubborn, willful) |
| unvarying(adjective, set, firm, solid, still) |
| wayward(adjective, tough, difficult, obstinate, stubborn) |
| wedged(firm, true, fixed, constant, steadfast) |
| adjusted(adjective, strong, solid, stable, sure) |
| affectless |