E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Applied to the four great religious ordersDominicans, Franciscans, Augustinians, and Carmelites. Later, a fifth order was addedthat of the Trinitarians. The first two were called Black and Grey friars, the Carmelites were called White friars, and the Trinitarians Crutched friars (q.v.).