IPA: /rɪˈmɔːsləsli/
KK: /rɪˈmɔrsləsli/
In a way that shows no regret or guilt for one's actions.
He pursued his goals remorselessly, ignoring the feelings of others.
Remorselessly → It is formed from "re-" (meaning again) and "morsus" (from Latin, meaning bite) combined with "-less" (meaning without) and "-ly" (meaning in a manner). The word describes acting in a manner that is without remorse or without the feeling of a 'bite' of guilt.
Think of someone acting 'without' ('-less') the 'bite' of guilt ('morsus') — that's why remorselessly means doing something without feeling sorry.