Adverb
in a heartless manner
Source: WordNetshe behaves rather heartlessly toward her admirers Source: Internet
The dramatic beauty and innocent hope of Ofelia’s imagination is contrasted with brutal violence and desperation in the real world, where Ofelia’s stepfather heartlessly tortures and murders, and her mother is extremely ill in her pregnancy. Source: Internet
“I am appalled that a private message to my daughter has been so heartlessly shared with the media,” said Mr. Spade. Source: Internet