Definition:
a brutal person; bully
Examples:
"'You try me too much. A ruffian - a common brawling ruffian - that's what you have become.'" - Arthur Conan Doyle, The Lost World, 1912
"Tintin always moves (unless he's been knocked out by some ruffian). Motion is his appeal and the reason Steven Spielberg's representation rings true." - Matt Easton, The Michigan Daily, January 4, 2012
About the Word:
Ruffians specialize in roughness, and between the 16th and 18th centuries, they were also synonymous with pimps - men who solicit clients for prostitutes.