Crossword tournament competitor on a 2008 "Simpsons" episode (4)
I believe the answer is:
lisa
(Other definitions for lisa that I've seen before include "Girl" , "Leonardo da Vinci painted the 'Mona ....'" , "Mona ..., also called La Gioconda" , "Most intelligent of Marge Simpson's children" , "Mona . . . ., famous painting by Leonardo da Vinci" .)