Pau-Wa-Lu Middle School produced two spelling champs on Tuesday, but it wasn't easy.Certain words during the Douglas County School District's seventh- and eighth-grade finals seemed plucked from obscurity, dredged from esoteric corners of the lexicon, such as "ocarina," a small, often ceramic wind instrument, or "nonagenarian," a person between 90 and 100 years old. Other words had a distinct, shall we say, flavor, like "chalupa," and "tamale."Pau-Wa-Lu librarian and event moderator Susan Bullard explained that the spelling bee word list is varied and relies on "the luck of the draw." Some spellers may know every word except the one they …