IPA: /rɪˈmɔːsləsnəs/
KK: /rɪˈmɔrsləsnəs/
The quality of not feeling regret or guilt for one's actions.
His remorselessness made it difficult for others to forgive him for his mistakes.
Remorselessness → It is formed from "re-" (meaning again) and "mors" (from Latin "mors", meaning death) and "-less" (meaning without) and "-ness" (meaning the state of). The word describes the state of being without remorse or the feeling of guilt again, particularly in the context of causing harm or death.
Think of being 'without' ('-less') the feeling of guilt ('mors' relates to death) — that's what remorselessness means.