← BackshareGuesslackaday/ˈlækəˌdeɪ/interjectionAn old-fashioned exclamation used to express sadness, regret, or disappointment.Lackaday, she thought, another day wasted.He sighed, 'Lackaday, the picnic is ruined by the rain.'Lackaday! I have lost my favorite book.SynonymsalaswoeAntonymshurray