Meaning: a woman who is a man's sweetheart
Dulcinea is illustrious and well-born, and of one of the gentle families of El Toboso, which are many, ancient, and good.
I have mentioned this lest anybody should mind what Sancho said about Dulcinea's winnowing or sifting; for, as they changed her to me, it is no wonder if they changed her to him.
"So I say," said Sancho, "and if my lady Dulcinea is enchanted, so much the worse for her, and I'm not going to pick a quarrel with my master's enemies, who seem to be many and spiteful.
The truth is that the one I saw was a country wench, and I set her down to be a country wench; and if that was Dulcinea it must not be laid at my door, nor should I be called to answer for it or take the consequences.
"There is a good deal to be said on that point," said Don Quixote; "God knows whether there be any Dulcinea or not in the world, or whether she is imaginary or not imaginary; these are things the proof of which must not be pushed to extreme lengths.
Dulcinea, besides, has that within her that may raise her to be a crowned and sceptred queen; for the merit of a fair and virtuous woman is capable of performing greater miracles; and virtually, though not formally, she has in herself higher fortunes."
The duchess begged Don Quixote, as he seemed to have a retentive memory, to describe and portray to her the beauty and features of the lady Dulcinea del Toboso, for, judging by what fame trumpeted abroad of her beauty, she felt sure she must be the fairest creature in the world, nay, in all La Mancha.
For in truth and earnest, I know from good authority that the coarse country wench who jumped up on the ass was and is Dulcinea del Toboso, and that worthy Sancho, though he fancies himself the deceiver, is the one that is deceived; and that there is no more reason to doubt the truth of this, than of anything else we never saw.
But I cannot help entertaining a doubt, and having a certain grudge against Sancho Panza; the doubt is this, that the aforesaid history declares that the said Sancho Panza, when he carried a letter on your worship's behalf to the said lady Dulcinea, found her sifting a sack of wheat; and more by token it says it was red wheat; a thing which makes me doubt the loftiness of her lineage."
Sancho upon this related to her, word for word, what has been said already touching that adventure, and having heard it the duchess said, "From this occurrence it may be inferred that, as the great Don Quixote says he saw there the same country wench Sancho saw on the way from El Toboso, it is, no doubt, Dulcinea, and that there are some very active and exceedingly busy enchanters about."