IPA: /rɪˈɡrɛtfəl/
KK: /rɪˈɡrɛtfəl/
Feeling sad or sorry about something that has happened or been done.
She felt regretful after realizing she had hurt her friend's feelings.
Regretful → It is formed from "regret" (from Latin "regretare", meaning to weep again) and "-ful" (meaning full of). The word "regretful" means full of regret or sorrow for something that has happened.
Think of feeling 'full of sorrow' for something that has happened — 'regret' means to weep again, and '-ful' means full of.