In a manner that is criminal, traitorous, or involves intentional wrongdoing; with felonious intent or character.
From 'felonious' (adjective), derived from Old French 'felon,' meaning wicked or evil. The -ly adverbial suffix was added in Middle English.
When prosecutors say someone acted 'feloniously,' they're invoking a word that originally meant 'wickedly'—it signals moral judgment, not just legal violation, distinguishing murder from manslaughter.
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