Green’s Dictionary of Slang

a rough person, a thug.

1707		J. Shirley Triumph of Wit (5th edn) 186: Not suffering them to be abused by any strange Pallards, Ruffres, Hookers, Swadlers, Irish Toyls, Dummerers, Jarkmen, Whipjacks, Glimmerers, Maunders, or the like, or any other Out-lyers.
1754		Scoundrel’s Dict. 15: A stout Rogue – Ruffer.
1909		J. Ware Passing Eng. of the Victorian Era.