Been receiving for the past 2 weeks the "Word of the Day" from Dictionary.com. Have posted the ones I didn't know of here, but 2/3rds of the remaining ones, are French words! So French words would be the hardest English words?
maladroit \mal-uh-DROYT\, adjective:
Lacking adroitness; clumsy; awkward; unskillful; inept.
Reminded me of an article on the Christian Science Monitor website untitled English Sans French.