Felonious

Done with an intent to commit a serious crime or a felony; done with an evil heart or purpose; malicious; wicked; villainous.

An aggravated assault, such as an assault with an intent to murder, is a felonious assault. A simple assault, such as one done with an intent to frighten, is not felonious.

---

felonious adj. referring to an act done with criminal intent. The term is used to distinguish between a wrong which was not malicious, and an intentional crime, as in "felonious assault," which is an attack meant to do real harm.