| No. | Item | Definition |
|---|---|---|
| 1. | absolutely | completely; without reservation |
| 2. | actually | in fact; as the truth |
| 3. | adamantly | with firm determination |
| 4. | ardently | with intense sincerity |
| 5. | assiduously | with persistent, careful effort |
| 6. | assuredly | certainly; confidently |
| 7. | attentively | with careful attention |
| 8. | austerely | in a strict, serious way |
| 9. | believe me | trust me; I’m serious |
| 10. | candidly | in a frank, honest way |
| 11. | carefully | with care and seriousness |
| 12. | certainly | without doubt; surely |
| 13. | consciously | with awareness; deliberately |
| 14. | considerately | with careful consideration |
| 15. | dead serious | completely serious |
| 16. | deadly earnest | extremely earnest |
| 17. | deadly serious | extremely serious |
| 18. | definitely | clearly; without uncertainty |
| 19. | deliberately | on purpose; with care |
| 20. | determinedly | with determination |
| 21. | devoutly | with deep sincerity |
| 22. | diligently | with steady, serious effort |
| 23. | earnestly | in a serious, sincere way |
| 24. | emphatically | with strong emphasis |
| 25. | fervently | with strong, sincere feeling |
| 26. | firmly | with strength and seriousness |
| 27. | for real | seriously; genuinely |
| 28. | for sure | certainly; without doubt |
| 29. | forcefully | with force; strongly |
| 30. | formally | in a formal, serious way |
| 31. | frankly | in an open, direct way |
| 32. | genuinely | in a real, sincere way |
| 33. | gravely | in a serious, solemn way |
| 34. | honestly | in an honest, frank way |
| 35. | in a serious way | not joking; earnestly |
| 36. | in all candor | with full frankness |
| 37. | in all honesty | honestly; sincerely |
| 38. | in all seriousness | speaking seriously, not joking |
| 39. | in dead earnest | completely serious; not joking |
| 40. | in earnest | seriously; not as a joke |
| 41. | in fact | actually; as a matter of fact |
| 42. | in good faith | with sincere intent |
| 43. | in no uncertain terms | very clearly and firmly |
| 44. | in plain English | clearly; simply |
| 45. | in plain terms | clearly; without softening |
| 46. | in seriousness | in a serious manner |
| 47. | in sober truth | in plain, serious truth |
| 48. | in truth | truly; in fact |
| 49. | incontestably | in a way not contestable |
| 50. | indeed | used to emphasize truth |
| 51. | indisputably | in a way not disputed |
| 52. | intentionally | on purpose; deliberately |
| 53. | intently | with focused seriousness |
| 54. | irrefutably | in a way not refutable |
| 55. | keenly | with sharp attention |
| 56. | legitimately | in a real, valid way |
| 57. | let me be clear | I mean this seriously |
| 58. | literally | without exaggeration; truly |
| 59. | make no mistake | be certain; understand clearly |
| 60. | mindfully | with attentive awareness |
| 61. | no joke | not joking; truly |
| 62. | no kidding | I mean it; truly |
| 63. | no question | certainly; without debate |
| 64. | not joking | in earnest; not in fun |
| 65. | not kidding | not joking; truly |
| 66. | passionately | with strong feeling, seriously |
| 67. | plainly | clearly and directly |
| 68. | positively | certainly; emphatically |
| 69. | properly | in a correct, serious way |
| 70. | purposefully | with purpose; intentionally |
| 71. | real talk | honest talk; no joking |
| 72. | really | actually; in reality |
| 73. | resolutely | with firm resolve |
| 74. | respectfully | with due seriousness and respect |
| 75. | reverently | with deep respect and seriousness |
| 76. | serious-mindedly | with a serious attitude |
| 77. | severely | in a harsh, serious way |
| 78. | sincerely | with genuine feeling or intent |
| 79. | soberly | in a serious, calm way |
| 80. | solemnly | in a formal, serious way |
| 81. | somberly | in a gloomy, serious way |
| 82. | sternly | in a strict, serious way |
| 83. | straight | directly; without joking |
| 84. | studiously | with careful, serious effort |
| 85. | surely | certainly; without doubt |
| 86. | thoughtfully | with careful thought |
| 87. | to be candid | speaking frankly |
| 88. | to be clear | to clarify seriously |
| 89. | to be frank | speaking openly and honestly |
| 90. | to be honest | frankly; honestly |
| 91. | to tell the truth | honestly; in truth |
| 92. | truly | in fact; genuinely |
| 93. | truth be told | to be honest |
| 94. | truthfully | in a truthful manner |
| 95. | undoubtedly | with no doubt at all |
| 96. | unquestionably | beyond question; certainly |
| 97. | unwaveringly | without changing; firmly |
| 98. | vehemently | with intense force |
| 99. | verily | truly; certainly |
| 100. | without doubt | certainly; unquestionably |