| No. | Item | Definition |
|---|---|---|
| 1. | adamant | unyielding; refusing to change |
| 2. | agonizing | causing great pain |
| 3. | arduous | very difficult; tiring |
| 4. | austere | plain and severe |
| 5. | awful | very bad or unpleasant |
| 6. | awkward | difficult to handle or do |
| 7. | backbreaking | extremely physically demanding |
| 8. | baffling | very confusing; hard to explain |
| 9. | bleak | cold, harsh, or hopeless |
| 10. | brittle | hard but easily broken |
| 11. | brutal | very harsh or painful |
| 12. | burdensome | hard to carry or endure |
| 13. | challenging | demanding skill or effort |
| 14. | compact | tightly packed; firm |
| 15. | complicated | made of many parts; difficult |
| 16. | compressed | pressed into smaller space |
| 17. | critical | very serious; decisive |
| 18. | cruel | causing pain; unkind |
| 19. | daunting | seeming difficult to deal with |
| 20. | demanding | requiring much effort or skill |
| 21. | dense | closely packed; thick |
| 22. | determined | having a firm decision |
| 23. | difficult | not easy; requiring effort |
| 24. | dogged | stubbornly persistent |
| 25. | draconian | extremely harsh or severe |
| 26. | draining | using up energy or strength |
| 27. | elusive | hard to find or grasp |
| 28. | exacting | requiring great precision or effort |
| 29. | excruciating | extremely painful |
| 30. | exhausting | making very tired |
| 31. | extreme | very great in degree |
| 32. | ferocious | savagely fierce or intense |
| 33. | fierce | violent or intense |
| 34. | firm | strongly fixed; not yielding |
| 35. | flinty | hard and unyielding |
| 36. | forceful | strong and effective |
| 37. | formidable | intimidatingly difficult |
| 38. | grim | very serious or harsh |
| 39. | grueling | extremely tiring and difficult |
| 40. | hardcore | very intense or extreme |
| 41. | hardened | made firm or tough |
| 42. | hardheaded | practical; not sentimental |
| 43. | hardline | firm and uncompromising |
| 44. | harsh | severe; unpleasantly rough |
| 45. | heavy | difficult or burdensome |
| 46. | impenetrable | not able to be entered |
| 47. | impervious | not affected; not penetrable |
| 48. | inflexible | not easily bent or changed |
| 49. | intense | very strong or extreme |
| 50. | intransigent | unwilling to compromise |
| 51. | intricate | very detailed and complex |
| 52. | killing | extremely tiring or hard |
| 53. | knotty | complicated and difficult |
| 54. | laborious | taking much work or time |
| 55. | merciless | showing no mercy |
| 56. | miserable | very unhappy or uncomfortable |
| 57. | mystifying | hard to understand |
| 58. | nasty | very unpleasant or harsh |
| 59. | no-nonsense | practical and strict |
| 60. | obdurate | stubbornly refusing to change |
| 61. | obscure | not clear; hard to understand |
| 62. | onerous | burdensome; hard to do |
| 63. | opaque | hard to understand; not clear |
| 64. | oppressive | unpleasantly harsh or heavy |
| 65. | painful | causing physical or emotional pain |
| 66. | perplexing | confusing and difficult |
| 67. | persistent | continuing despite difficulty |
| 68. | pitiless | showing no pity |
| 69. | punishing | very harsh or difficult |
| 70. | puzzling | hard to understand or explain |
| 71. | relentless | not easing or stopping |
| 72. | resistant | hard to affect or change |
| 73. | resolute | firmly determined |
| 74. | rigid | not flexible; stiff |
| 75. | rigorous | strict and demanding |
| 76. | rough | not smooth; uneven |
| 77. | ruthless | without pity; harsh |
| 78. | severe | very intense or harsh |
| 79. | solid | firm; not soft |
| 80. | steadfast | firmly loyal or resolute |
| 81. | steely | hard, cold, and strong |
| 82. | stern | serious and strict |
| 83. | stiff | not easily bent |
| 84. | strenuous | requiring great physical effort |
| 85. | stubborn | not willing to change |
| 86. | taxing | draining effort or resources |
| 87. | tenacious | holding firmly; persistent |
| 88. | terrible | very bad; severe |
| 89. | tight | difficult due to limited resources |
| 90. | tough | hard to do or endure |
| 91. | trying | stressful; hard to endure |
| 92. | uncompromising | not making concessions |
| 93. | unforgiving | not tolerant of mistakes |
| 94. | unpleasant | not enjoyable; disagreeable |
| 95. | unrelenting | not becoming less severe |
| 96. | unyielding | not giving way under pressure |
| 97. | violent | using great force |
| 98. | wearing | tiring over time |
| 99. | weighty | serious and difficult |
| 100. | wretched | very miserable or bad |
