We don't have synonyms for felonies yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are felonious, melodies and felons.
(n) :
(law, criminology, US, historical in UK) A serious criminal offense, which, under United States federal law, is punishable by a term of imprisonment of not less than one year or by the death penalty in the most serious offenses.
(n) :
(law, criminology, US, historical in UK) A serious criminal offense, which, under United States federal law, is punishable by a term of imprisonment of not less than one year or by the death penalty in the most serious offenses.