used to describe something that you are sorry about and wish had not happened Regrettably, crime has been increasing in this area. This fine restaurant has, regrettably, gone out of business. There is regrettably little evidence to support this argument. Which Word?regretfully / regrettably Regretfully and regrettably can both be used as sentence adverbs to show that you are sorry about something and wish the situation were different:Regretfully, some jobs will be lost. Regrettably, some jobs will be lost. Regretfully can also be used to mean ‘in a way that shows you are sad or disappointed about something’:He sighed regretfully.