| No. | Item | Definition |
|---|---|---|
| 1. | abecedarian | elementary or beginner-level |
| 2. | all-important | most important of all |
| 3. | animating | giving essential energy or life |
| 4. | at the heart of | at the central point of |
| 5. | at the root of | at the basic cause of |
| 6. | axiomatic | obviously true as a basic principle |
| 7. | backbone | main supporting strength |
| 8. | basal | forming a base |
| 9. | base | forming the bottom support |
| 10. | basic | forming the main foundation |
| 11. | basis | underlying support or reason |
| 12. | bedrock | most basic supporting part |
| 13. | benchmark | standard point for comparison |
| 14. | big-picture | focused on the main essentials |
| 15. | capital | chief or principal |
| 16. | cardinal | of greatest importance |
| 17. | central | most important or main |
| 18. | chief | highest in importance |
| 19. | constitutive | forming an essential part |
| 20. | core | at the center or heart |
| 21. | critical | extremely important |
| 22. | crucial | extremely important or decisive |
| 23. | decisive | settling an issue importantly |
| 24. | deep-rooted | firmly established at the base |
| 25. | deep-seated | firmly fixed and basic |
| 26. | determinative | deciding the outcome |
| 27. | dominant | most influential or central |
| 28. | driving | providing the main force |
| 29. | elemental | relating to basic parts |
| 30. | elementary | dealing with the simplest basics |
| 31. | essential | absolutely necessary or central |
| 32. | fabric | basic structure of something |
| 33. | first principles | most basic truths or assumptions |
| 34. | first-order | of highest basic importance |
| 35. | foremost | most important or first |
| 36. | foundational | serving as a base |
| 37. | framework | basic supporting structure |
| 38. | governing | serving as the main guide |
| 39. | grassroots | at the most basic level |
| 40. | ground-floor | at the earliest basic stage |
| 41. | ground-level | at the basic level |
| 42. | imperative | urgently necessary |
| 43. | indispensable | too important to do without |
| 44. | infrastructure | basic underlying systems |
| 45. | inherent | existing as a basic quality |
| 46. | innate | present from the beginning |
| 47. | integral | necessary to make whole |
| 48. | intrinsic | belonging naturally and essentially |
| 49. | irreducible | unable to be simplified further |
| 50. | key | crucially important |
| 51. | keystone | central supporting element |
| 52. | leading | most important or prominent |
| 53. | life-and-death | of utmost importance |
| 54. | linchpin | person or thing holding all together |
| 55. | lowest-level | at the simplest level |
| 56. | main | most important or chief |
| 57. | major | important or significant |
| 58. | mandatory | required by rule or need |
| 59. | material | important and relevant |
| 60. | mission-critical | essential for operation or success |
| 61. | momentous | very important |
| 62. | must-have | absolutely necessary item or feature |
| 63. | native | natural or inborn |
| 64. | necessary | needed or required |
| 65. | needful | necessary or required |
| 66. | nonnegotiable | not open to omission |
| 67. | nuts and bolts | basic practical details |
| 68. | obligatory | required by duty or rule |
| 69. | of the essence | absolutely central and urgent |
| 70. | operative | currently working as the main factor |
| 71. | organic | natural and essential to structure |
| 72. | overarching | covering the main whole |
| 73. | paramount | more important than anything else |
| 74. | part and parcel | an essential involved part |
| 75. | pivotal | centrally important to development |
| 76. | primary | first in importance |
| 77. | prime | first in rank or importance |
| 78. | primitive | very basic or undeveloped |
| 79. | principal | chief or most important |
| 80. | requisite | officially or practically required |
| 81. | root | source or basic cause |
| 82. | rudimentary | basic and not advanced |
| 83. | rule-of-thumb | basic practical guideline |
| 84. | scaffolding | supporting basic structure |
| 85. | sine qua non | an essential condition |
| 86. | skeleton | basic underlying structure |
| 87. | stripped-down | reduced to basic parts |
| 88. | structural | forming the main framework |
| 89. | substantive | having real importance or substance |
| 90. | substructure | underlying supporting structure |
| 91. | systemic | affecting the whole system |
| 92. | texture | basic character or structure |
| 93. | top | highest in importance |
| 94. | touchstone | basic standard for judgment |
| 95. | unavoidable | not able to be avoided |
| 96. | underlying | lying beneath the surface |
| 97. | warp and woof | basic structure or substance |
| 98. | weighty | important and serious |
| 99. | whole-system | involving the entire system |
| 100. | yardstick | basic standard of measurement |
