| Mot | Nature | Origine |
|---|---|---|
| illégalement | adverbe | illégalement |
| illégitimement | adverbe | illégitimement |
| illicitement | adverbe | illicitement |
| illico | adverbe | illico |
| illisiblement | adverbe | illisiblement |
| illogiquement | adverbe | illogiquement |
| illusoirement | adverbe | illusoirement |