E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Uncumber (St.),
formerly called St. Wylgeforte. Women changed her name (says Sir Thomas More) because they reken that for a pecke of otys she will not faile to uncumber them of their husbondys. The tradition says that the saint was very beautiful, but, wishing to lead a single life, prayed that she might have a beard, after which she was no more cumbered with lovers. For a peck of oats, says Sir Thomas More, she would provide a horse for an evil housebonde to ride to the Devill upon.
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If a wife were weary of a husband, she offered oats at Poules to St. Uncumber.Michael Woode (1554).