When it comes to finding synonyms for the word "deadhearted," words that can be used to describe someone who lacks compassion, empathy, or any sort of emotional connection, there are many options to choose from. Some of the commonly used words that come to mind are apathetic, callous, cold-blooded, emotionless, heartless, inconsiderate, indifferent, merciless, pitiless, unfeeling, and unresponsive. These words showcase a lack of sensitivity, concern, or care for the feelings or experiences of others. They are often used to describe people who are cruel, selfish, or detached, and who show little to no regard for the impact of their actions or words on others.