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