Amos, the word "yepe" become, over the centuries, "ept" and from that, of course we also derive "inept" (e.g., "He was as inept as a carpenter as he was as a poet").

I already knew the word "quiddity", not only because I studied Latin when young and have a large vocabulary, but also because my wife's a lawyer. (Please note the "not only...but also" construction in the foregoing sentence. That's the kind of thing us English Majors learned.)