The word "regretless" means without regret or remorse. There are several synonyms that can be used to describe this feeling, including: 1. Remorseless: This word is often used to describe someone who shows no remorse for their actions or behavior. 2. Unrepentant: Similar to remorseless, unrepentant is used to describe someone who does not regret their actions. 3. Shameless: This word is often used to describe someone who shows no shame or guilt for their actions. 4. Carefree: This word can be used to describe someone who lives without regret or worry. 5. Guiltless: This word is often used to describe someone who is not guilty or responsible for a particular action. Overall, there are many different words that can be used to describe the feeling of living without regret, and each word brings a slightly different nuance to the meaning.