1. Inadequate: Not sufficient, lacking in quality. Etymologically, this word comes from the Latin in- and adaequare, meaning "not equal".

2. Inanimate: Not alive; without life or animation. Etymologically, this word comes from the Latin in- and anima, meaning "without spirit".

3. Inaudible: Not able to be heard. Etymologically, this word comes from the Latin in- and audire, meaning "not to hear".

4. Illogical: Not rational, not based on sound reasoning. Etymologically, this word comes from the Latin illogicus, meaning "not reasonable".

5. Immaterial: Not composed of physical matter; having no material form. Etymologically, this word comes from the Latin in- and materia, meaning "without matter".

6. Impossible: Not able to be done or accomplished. Etymologically, this word comes from the Latin in- and possibilis, meaning "not able to be done".

7. Inaction: not taking action; inactive. Etymologically, it comes from the Latin, “inactus”, meaning “not active”.

8. Inadaptable: not able to adjust. Etymologically, it comes from the Latin, “inadaptabilis”, meaning “not able to be adapted”.

9. Impertinent: not appropriate; rude. Etymologically, it comes from the Latin, “impertinens”, meaning “not pertinent”.

10. Illiterate: not able to read; ignorant. Etymologically, it comes from the Latin, “illiteratus”, meaning “not literate”.

11. Impenetrable: not penetrable; impossible to understand. Etymologically, it comes from the Latin, “impenetrabilis”, meaning “not able to be penetrated”.

12. Impolite: not polite; rude. Etymologically, it comes from the Latin, “impolitus”, meaning “not polished”.

13. Incompatible: not compatible; unable to coexist. Etymologically, it comes from the Latin, “incomparabilis”, meaning “not equal”.

14. Impractical: not practical; not useful. Etymologically, it comes from the Latin, “impracticus”, meaning “not able to be done”.