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1.
Saint Sexburgha founded the abbey (no, I don't know why it wasn't a convent, what with her being a nun and all that) in Minster, on the Isle of Sheppey on the Thames Estuary.

When I lived on Sheppey, the rev. at the Abbey had two cats called Sexy and Burgha.

Now that it's on UD, it'll probably turn out to be slang for some obscene act of venery, too.
Sexburgha succeeded her sister as abbess of Ely in 679 and oversaw the translation of Etheldreda's* incorrupt relics to the cathedral at Ely.

*her sister, also a saint - saintliness obviously ran in the family, and 2 of Sexburgha's daughters were also canonised
by mathilda underfoot March 21, 2010