REGRETFUL
regretful, sorry, bad
(adjective) feeling or expressing regret or sorrow or a sense of loss over something done or undone; “felt regretful over his vanished youth”; “regretful over mistakes she had made”; “he felt bad about breaking the vase”
Source: WordNet® 3.1
Etymology
Adjective
regretful (comparative more regretful, superlative most regretful)
Full of feelings of regret, indulging in regrets.
Sorrowful about what has been lost or done.
Synonyms
• (full of regret): repining, rueful, sorrowful
Source: Wiktionary
Re*gret"ful (-fl), a.
Definition: Full of regret; indulging in regrets; repining.
– Re*gret"ful*ly, adv.
Source: Webster’s Unabridged Dictionary 1913 Edition