Before revision: Duenna English-speaking cultures supposed, perhaps correctly, that the institution was particularly strict in southern Europe, especially in Spain, to which they attributed the word duenna, a misspelling of the Spanish word "dueña".The Spanish word dueña was supposed to denote a particularly eagle-eyed supervisor of unmarried females.
After revision: Duenna English-speaking cultures supposed, perhaps correctly, that the institution was particularly strict in southern Europe, especially in Spain, to which they attributed the word duenna, an Old Spanish spelling (ñ evolved from one n written above another) of the modern Spanish word "dueña".The Spanish word dueña was supposed to denote a particularly eagle-eyed supervisor of unmarried females.