What does "felonious" mean?

Felonious: Having the quality of felony; malignant; malicious; villainous; traitorous; perfidious; in a legal sense, done with intent to commit a crime; as, felonious homicide. O thievish Night, Why should'st thou, but for some felonious end, In thy dark lantern thus close up the stars Milton. -- Fe*lo"ni`ous*ly, adv. -- Fe*lo"ni`ous*ness, n.