| No. | Item | Definition |
|---|---|---|
| 1. | adamant | refusing to change position |
| 2. | air-tight | tightly sealed; secure |
| 3. | anchored | securely held in place |
| 4. | assertive | confidently direct and firm |
| 5. | authoritative | confident and commanding |
| 6. | backed | supported strongly |
| 7. | bent on | strongly determined to do |
| 8. | binding | officially fixed and enforceable |
| 9. | blunt | direct and uncompromising |
| 10. | bolted | secured with a bolt |
| 11. | cast-iron | very strong and dependable |
| 12. | categorical | absolute and without exception |
| 13. | clear-cut | plainly defined and firm |
| 14. | committed | firmly dedicated to something |
| 15. | compact | closely packed together |
| 16. | compressed | pressed into less space |
| 17. | conclusive | decisive and final |
| 18. | constant | remaining the same over time |
| 19. | decisive | showing clear, firm choice |
| 20. | dedicated | devoted and unwavering |
| 21. | definite | clear, fixed, and certain |
| 22. | dense | closely compacted or thick |
| 23. | dependable | reliable and trustworthy |
| 24. | determined | having a fixed purpose |
| 25. | dogged | showing stubborn determination |
| 26. | durable | able to last well |
| 27. | emphatic | expressed with force and certainty |
| 28. | enforceable | able to be upheld legally |
| 29. | entrenched | firmly established and hard to change |
| 30. | established | firmly accepted or set |
| 31. | fast | firmly fixed in place |
| 32. | fastened | securely attached or closed |
| 33. | final | not open to change |
| 34. | fixed | securely placed; not movable |
| 35. | forceful | strong and assertive |
| 36. | formidable | impressively strong or firm |
| 37. | forthright | direct and straightforward |
| 38. | founded | built on a basis |
| 39. | grounded | based on solid support |
| 40. | hard | not soft; resistant to pressure |
| 41. | hardened | made hard or tougher |
| 42. | hardline | very strict and uncompromising |
| 43. | hardy | strong and able to endure |
| 44. | harsh | stern and not gentle |
| 45. | immobile | unable to move |
| 46. | immovable | unable to be moved |
| 47. | inelastic | not flexible or stretchable |
| 48. | inflexible | not willing or able to bend |
| 49. | intent on | focused firmly on doing |
| 50. | intransigent | refusing to compromise |
| 51. | iron | very strong and unyielding |
| 52. | ironclad | extremely secure or certain |
| 53. | latched | closed with a latch |
| 54. | locked | secured against opening |
| 55. | nonnegotiable | not open to change |
| 56. | obdurate | stubbornly refusing to change |
| 57. | obstinate | stubborn and hard to persuade |
| 58. | open-and-shut | clear and beyond doubt |
| 59. | orthopedic | supportive and structurally firm |
| 60. | packed | filled tightly together |
| 61. | persistent | continuing firmly despite difficulty |
| 62. | positive | fully confident and certain |
| 63. | powerful | having great strength or force |
| 64. | purposeful | having clear, firm intent |
| 65. | reinforced | made stronger or firmer |
| 66. | reliable | consistently trustworthy or effective |
| 67. | resistant | able to withstand force |
| 68. | resolute | firmly determined |
| 69. | resolved | firmly decided |
| 70. | rigid | stiff and not flexible |
| 71. | robust | strong and able to endure |
| 72. | rock-solid | extremely firm or reliable |
| 73. | rooted | firmly established or fixed |
| 74. | rugged | strong and rough-built |
| 75. | sealed | closed tightly and securely |
| 76. | secure | safe and firmly fixed |
| 77. | set | fixed into position |
| 78. | solid | strong and not easily changed |
| 79. | sound | reliable and in good condition |
| 80. | stable | steady and unlikely to shift |
| 81. | steadfast | firmly loyal or constant |
| 82. | steady | not wavering or changing |
| 83. | strong | powerful and hard to break |
| 84. | sturdy | strongly built or made |
| 85. | taut | pulled tight and tense |
| 86. | tempered | strengthened by treatment |
| 87. | tenacious | holding firmly; persistent |
| 88. | tight | firmly fixed or closed |
| 89. | tough | strong, strict, or hard |
| 90. | uncompromising | not willing to make concessions |
| 91. | unequivocal | leaving no doubt |
| 92. | unshakable | not able to be shaken |
| 93. | unwavering | not changing or weakening |
| 94. | unyielding | not giving way under pressure |
| 95. | valid | sound and acceptable |
| 96. | watertight | secure against flaws or leaks |
| 97. | well-fastened | securely attached |
| 98. | well-founded | based on solid reasons |
| 99. | well-grounded | supported by good reasons |
| 100. | well-secured | firmly attached or protected |