(2 syl.). French insurgents of the Royalist party during the Revolution. Jean Cottereau was their leader, nicknamed chouan (owl), because he was accustomed to warn his companions of danger by imitating the screech of an owl. Cottereau was followed by George Cadoudal.
It is an error to suppose Chouan to be a proper name.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894