Mother Hubbard

in reference to a kind of loose, full gown worn by women, 1878, from Old Mother Hubbard, nursery rhyme, which was printed 1805, written by Sarah Catherine Martin (1768-1826) but based on earlier material of unknown origin. The name is attested from 1591.

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Definitions of Mother Hubbard from WordNet

Mother Hubbard (n.)
a woman's loose unbelted dress;
Synonyms: muumuu