From The Collaborative International Dictionary of English v.0.48:
Varlet \Var"let\, n. [OF. varlet, vaslet, vallet, servant, young man, young noble, dim. of vassal. See Vassal, and cf. Valet.] [1913 Webster] 1. A servant, especially to a knight; an attendant; a valet; a footman. [Obs.] --Spenser. Tusser. [1913 Webster]
2. Hence, a low fellow; a scoundrel; a rascal; as, an impudent varlet. [1913 Webster]
What a brazen-faced varlet art thou ! --Shak. [1913 Webster]
3. In a pack of playing cards, the court card now called the knave, or jack. [Obs.] [1913 Webster]