E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A nickname. Ménage thinks the etymology is the Latin subridiculum (somewhat ridiculous); Count de Gebelin suggests the Romance words sopra-quest (a name acquired over and above your proper names); while Leglay is in favour of soubriquet, a word common in the fourteenth century to express a sound of contempt, half whistle and half jeer, made by raising quickly the chin. Probably sous-brechet, where brechet means the breast, seen in our word brisket.