Any person or character who displays quixotism.
A famous 1605–1615 Spanish novel by Miguel de Cervantes (1547–1616), whose full title is El ingenioso hidalgo don Quijote de la Mancha (The Ingenious Gentleman Don Quixote of La Mancha).
The protagonist of this novel.
of, or relating to defeatism
someone who advocates defeatism, or has such an attitude