| No. | Term | Definition |
|---|---|---|
| 1. | ad hoc | For the moment; not formalized. |
| 2. | advisory | Not binding; not formal. |
| 3. | affable | Friendly and easy in manner. |
| 4. | approachable | Easy and not formal. |
| 5. | approximate | Not exact; not formally precise. |
| 6. | as an aside | Informally; not part of formal talk. |
| 7. | at ease | Relaxed; free from formality. |
| 8. | back-of-the-envelope | Rough and informal; not exact. |
| 9. | backchannel | Unofficial, informal communication route. |
| 10. | behind the scenes | Unofficial; not publicly formalized. |
| 11. | buddy-buddy | Overly familiar and informal. |
| 12. | candid | Frank; not formal or guarded. |
| 13. | casual | Relaxed; not formal. |
| 14. | chatty | In a friendly, conversational style. |
| 15. | chummy | Friendly and informal. |
| 16. | colloquial | Used in everyday conversation. |
| 17. | commonplace | Ordinary; lacking formality. |
| 18. | conversational | Like ordinary speech; not formal. |
| 19. | cordial | Warm; not stiffly formal. |
| 20. | direct | Plain; without formalities. |
| 21. | down-to-earth | Practical and not formal. |
| 22. | easy | Relaxed; not formal. |
| 23. | easygoing | Laid-back; not rigidly formal. |
| 24. | everyday | Ordinary; not formal. |
| 25. | extemporaneous | Unrehearsed; not formally prepared. |
| 26. | familiar | Comfortably informal; not formal. |
| 27. | fireside | Warm, intimate, and informal. |
| 28. | flexible | Not fixed by formal rules. |
| 29. | frank | Direct; without formal restraint. |
| 30. | free-and-easy | Relaxed and informal. |
| 31. | friendly | Warm and not formal. |
| 32. | genial | Cheerful and informal. |
| 33. | good-natured | Kindly and not formal. |
| 34. | grassroots | Unofficial; from ordinary people. |
| 35. | hip | Fashionably informal; not formal. |
| 36. | homely | Plain and simple; not formal. |
| 37. | homespun | Plain and simple in style. |
| 38. | idiomatic | Natural to everyday speech. |
| 39. | impromptu | Done without preparation; informal. |
| 40. | in casual wear | Wearing everyday, not formal clothes. |
| 41. | in civilian clothes | Not in uniform; ordinary dress. |
| 42. | in mufti | In ordinary clothes, not uniform. |
| 43. | in plain clothes | Not in formal attire. |
| 44. | in street clothes | Not in uniform or formalwear. |
| 45. | informalized | Made less formal. |
| 46. | kitchen-table | Informal and practical in tone. |
| 47. | laid-back | Relaxed and unpretentious. |
| 48. | loose | Not strict or formal. |
| 49. | looser | Less strict; less formal. |
| 50. | low-key | Quietly relaxed; not formal. |
| 51. | matey | Overfriendly and informal. |
| 52. | matter-of-fact | Plain; without ceremony. |
| 53. | neighborly | Friendly and informal. |
| 54. | no-frills | Simple; without extra formality. |
| 55. | non-official | Not official; not formal. |
| 56. | nonbinding | Not legally or formally enforceable. |
| 57. | nonceremonial | Without ceremony or formality. |
| 58. | nonformal | Not formal in style. |
| 59. | nontechnical | Not technical or formally specialized. |
| 60. | nontheoretical | Practical; not formally theoretical. |
| 61. | off the record | Not for formal publication. |
| 62. | off to the side | Not in the formal main part. |
| 63. | off-the-cuff | Spoken without preparation; informal. |
| 64. | offhand | Not planned or formal. |
| 65. | on the fly | Done quickly without formal planning. |
| 66. | one-on-one | Private and informal; between two people. |
| 67. | open | Not formal; candid and relaxed. |
| 68. | ordinary | Not special or formal. |
| 69. | pally | Friendly in an informal way. |
| 70. | personal | Not official; individual in tone. |
| 71. | plain style | Simple and informal style. |
| 72. | plainspoken | Direct and not formal. |
| 73. | popular | For ordinary people; not formal. |
| 74. | private | Not public or formally announced. |
| 75. | relaxed | Not strict or ceremonious. |
| 76. | rough | Not polished or formal. |
| 77. | rule-of-thumb | Based on practice, not formal rules. |
| 78. | seat-of-the-pants | Done without formal planning. |
| 79. | simple | Plain; without formality. |
| 80. | slangy | Using slang; informal. |
| 81. | small-scale | Not large or formally organized. |
| 82. | spontaneous | Unplanned; not formal. |
| 83. | straight | Direct and informal in tone. |
| 84. | straightforward | Plain and not formal. |
| 85. | substandard | Below standard; not formally correct. |
| 86. | tacit | Unspoken; not formally stated. |
| 87. | unadorned | Plain; without formal embellishment. |
| 88. | unbuttoned | Relaxed; not stiffly formal. |
| 89. | undress | Not in formal dress. |
| 90. | unformal | Not formal; unofficial. |
| 91. | unfussy | Not elaborate or formal. |
| 92. | unofficial | Not formally approved or recognized. |
| 93. | unpretentious | Not showy or formal. |
| 94. | unstructured | Not arranged in a formal way. |
| 95. | vernacular | In the common spoken language. |
| 96. | without ceremony | Without formalities or ritual. |
| 97. | without formality | In an informal manner. |
| 98. | without the formalities | Without formal procedures. |
| 99. | word of mouth | Informal personal communication. |
| 100. | workaday | Ordinary; not formal. |