The name of the famous London street (Piccadilly) and that of Piccadilly Circus are thought to be named after piccadill, and in particular to Piccadilla House, which was apparently a depot of piccadill lace during the reign of Elizabeth I. The name is also linked to a tailor, called Robert Baker, who had built up a flourishing business in producing piccadills. In the early seventeenth century he seems to have bought a plot of land along what was then called Portugal Street, and built a house that came to be known as Piccadilly Hall. Soon Portugal Street, so it is said, came to be known as Piccadilly.
Source: The Shorter Oxford English Dictionary, s.v. 'piccadill'.
National Portrait Gallery online gallery (retrieved 23rd January 2016).
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