A first-rate actor; so called from the Roman Roscius, unrivalled for his grace of action, melody of voice, conception of character, and delivery. He was paid thirty pounds a day for acting; Pliny says four thousand a year, and Cicero says five thousand.
“What scene of death hath Roscius now to act?”
Shakespeare: 3 Henry VI., v. 6.
Another Roscius. So Camden terms Richard Burbage (1566-1619).
The British Roscius. Thomas Betterton, of whom Cibber says, “He alone was born to speak what only Shakespeare knew to write.” (1635-1710).
David Garrick (1716-1779).
The Roscius of France. Michel Boyron, generally called Baron. (1653-1729.) The Young Roscius. William Henry West Betty, who in fifty-six nights realised 34,000. (Died 1874, aged 84.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894