Felonious/fəˈləʊniəs/ Definition 1 of 1Pro Tip 1/3Serious Crimes Use 'felonious' for grave offenses, not minor violations like traffic tickets. The felonious act involved a bank heist. Pro Tip 2/3Legal Context 'Felonious' is mainly used within legal discussions or reports of criminal activities. The defendant's felonious conduct is detailed in the case file. Pro Tip 3/3Formality 'Felonious' is formal; in casual talk, 'criminal' or 'illegal' might be more common. The news covered the felonious acts of the public figure.