10 most difficult English words:
1. Abjure: formally reject or disavow a formerly held belief
2. Camaraderie: the quality of affording easy familiarity and sociability
3. Defunct: no longer in force or use; inactive
4. Ephemeral: anything short - lived, as an insect that lives only for a day
5. Incumbent: necessary as a duty or responsibility; morally binding
6. Instigate: provoke or stir up
7. Munificent: very generous
8. Rife: excessively abundant
9. Trite: repeated too often; overfamiliar through overuse
10. Ubiquitous: being present everywhere at once