duenna

Etymology

From Old Spanish duenna or dueña, from Vulgar Latin donna, from Latin domina (“Lady”). Doublet of dame.

noun

1. a chaperon of a young lady, usually an older woman.
   Then he placed her in a house and shut her up in a chamber, appointing ten old women as duennas to guard her, and forbade her to go forth to the Seven Palaces. 1949, Joseph Campbell, The Hero with a Thousand Faces
2. a governess or nanny.