re ‧ gret ‧ ful ‧ ly /rɪˈɡretf ə li/ BrE AmE adverb
[ Word Family: adverb : ↑ regrettably , ↑ regretfully ; adjective : ↑ regrettable , ↑ regretful ; verb : ↑ regret ; noun : ↑ regret ]
1 . feeling sad because you do not want to do what you are doing:
‘I must go,’ he said regretfully.
2 . [sentence adverb] formal used to talk about a situation that you wish was different or that you are sorry about SYN regrettably :
Regretfully, we do not have time to continue this discussion now.