| No. | Term | Definition |
|---|---|---|
| 1. | Adamant | Unyielding; firmly decided. |
| 2. | Austere | Severely simple; strict. |
| 3. | Battered | Worn by repeated blows. |
| 4. | Battle-hardened | Toughened by experience. |
| 5. | Brutal | Harsh; severe; unforgiving. |
| 6. | Calloused | Hardened from repeated friction. |
| 7. | Clenched | Tightly held; tense. |
| 8. | Coarse | Rough in texture or manner. |
| 9. | Craggy | Rugged; uneven; rough. |
| 10. | Dauntless | Fearless; hard to discourage. |
| 11. | Defiant | Resistant; boldly disobedient. |
| 12. | Difficult | Hard to do or deal with. |
| 13. | Durable | Able to withstand wear. |
| 14. | Enduring | Lasting; able to persist. |
| 15. | Exacting | Demanding; requiring great effort. |
| 16. | Fierce | Intense; ferocious; forceful. |
| 17. | Firm | Solid; not easily moved. |
| 18. | Formidable | Hard to overcome; intimidating. |
| 19. | Gritty | Showing courage and resolve. |
| 20. | Grueling | Extremely tiring and demanding. |
| 21. | Hard | Not easily broken or done. |
| 22. | Hard-bitten | Toughened by hardship. |
| 23. | Hard-boiled | Unsentimental; resilient; tough-minded. |
| 24. | Hardy | Robust; able to endure. |
| 25. | Harsh | Severe; unpleasantly rough. |
| 26. | Hefty | Large and heavy; substantial. |
| 27. | Hulking | Massive and heavy-looking. |
| 28. | Immovable | Not able to be moved. |
| 29. | Implacable | Unappeasable; relentless. |
| 30. | Inflexible | Not willing to bend or change. |
| 31. | Intransigent | Uncompromising; stubbornly resistant. |
| 32. | Ironclad | Strongly protected; unbreakable. |
| 33. | Jagged | Rough with sharp points. |
| 34. | Jagged-edged | Rough; sharply uneven. |
| 35. | Jarring | Harshly disturbing; unpleasant. |
| 36. | Jolting | Suddenly rough or shocking. |
| 37. | Knotted | Tangled or tightly tightened. |
| 38. | Knotty | Difficult; complex; intricate. |
| 39. | Leathery | Tough and flexible like leather. |
| 40. | Long-suffering | Patient under prolonged hardship. |
| 41. | Merciless | Showing no pity; harsh. |
| 42. | Mighty | Very strong and powerful. |
| 43. | Misc: as nails | Extremely hard and resilient. |
| 44. | Misc: built like a tank | Very solid and durable. |
| 45. | Misc: hard as iron | Extremely hard; unyielding. |
| 46. | Misc: hard as stone | Extremely hard; unyielding. |
| 47. | Misc: iron-nerved | Calm under pressure; fearless. |
| 48. | Misc: rough-and-ready | Practical; hardy; unrefined. |
| 49. | Misc: take-no-prisoners | Aggressively uncompromising. |
| 50. | Misc: thick as a brick | Very solid; hard to break. |
| 51. | Misc: tough-minded | Unsympathetic; emotionally resilient. |
| 52. | Misc: tried and tested | Proven reliable under strain. |
| 53. | Monolithic | Massive; solid; hard to change. |
| 54. | Muscular | Strong; powerfully built. |
| 55. | Nerve-racking | Extremely stressful; anxiety-inducing. |
| 56. | No-nonsense | Practical; firm; unsentimental. |
| 57. | Obdurate | Stubborn; refusing to change. |
| 58. | Obstinate | Stubbornly persistent. |
| 59. | Oppressive | Heavy; harsh; hard to endure. |
| 60. | Overpowering | Too strong to resist. |
| 61. | Pugnacious | Eager to fight; combative. |
| 62. | Punishing | Severely demanding or harsh. |
| 63. | Ragged | Torn; rough; worn. |
| 64. | Razor-edged | Very sharp; cutting. |
| 65. | Relentless | Unceasing; harshly persistent. |
| 66. | Resilient | Quick to recover; tough. |
| 67. | Rigorously demanding | Requiring strict effort. |
| 68. | Rugged | Rough; strongly built. |
| 69. | Ruthless | Cruel; without mercy. |
| 70. | Severe | Very strict or harsh. |
| 71. | Shatterproof | Not easily broken. |
| 72. | Sinewy | Lean, strong, and tough. |
| 73. | Solid | Firm and stable; not hollow. |
| 74. | Spartan | Austere; disciplined; hardy. |
| 75. | Steadfast | Firmly loyal; unwavering. |
| 76. | Steely | Hard; coldly determined. |
| 77. | Stiff | Rigid; not easily bent. |
| 78. | Stout | Strong; thick; sturdy. |
| 79. | Strenuous | Requiring great physical effort. |
| 80. | Strict | Demanding exact obedience. |
| 81. | Stubborn | Unwilling to change or yield. |
| 82. | Sturdy | Strongly built; durable. |
| 83. | Tenacious | Holding firmly; persistent. |
| 84. | Thick-skinned | Not easily hurt by criticism. |
| 85. | Tight-lipped | Unwilling to reveal feelings. |
| 86. | Toilsome | Requiring much hard work. |
| 87. | Tortuous | Full of twists; difficult. |
| 88. | Trying | Annoyingly difficult; stressful. |
| 89. | Unbending | Not yielding; inflexible. |
| 90. | Uncompromising | Not making concessions. |
| 91. | Unforgiving | Harsh; not allowing mistakes. |
| 92. | Unrelenting | Not easing in intensity. |
| 93. | Unshakeable | Not easily disturbed or changed. |
| 94. | Unsparing | Not showing mercy; severe. |
| 95. | Unyielding | Not giving way; firm. |
| 96. | Vigorous | Strong, active, and energetic. |
| 97. | Vindictive | Spitefully harsh; vengeful. |
| 98. | Virile | Strong; vigorous; manly. |
| 99. | Weathered | Worn by exposure; seasoned. |
| 100. | Well-armored | Strongly protected; hard to harm. |