You can describe a smooth-talking, no-good man as a roue. You could also call him a lady's man, a rake, or a Lothario.
This one deserves a full etymology: it's French, a participle of rouer, "to break on the wheel," and it's also the name first applied to the profligate companions of the Duc d'Orléans. So in other words, a roue is a really bad dude. Roue is not common in conversation but that didn't stop Oscar Hammerstein from lyricizing it in "The Sound of Music:" "Eager young lads and roues and cads / Will offer you food and wine."