In a manner that is extremely wicked, shocking, or morally repugnant; with deep abhorrence or revulsion.
From 'heinous' (Old French 'haineus' meaning hateful, from 'haine' meaning hatred) plus the adverbial suffix '-ly,' forming an adverb that intensifies the adjective's meaning of extreme wickedness.
While 'evil' is neutral and 'wickedly' is playful, 'heinously' carries a specific flavor of moral disgust—it's the adverb reserved for acts that should make society shudder collectively.
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