sweetheart1 of 3interjection/ˈswitˌhɑrt/1used to address a loved one in an affectionate mannerB1Good morning, sweetheart.Don't worry, sweetheart, everything will be okay.Don't worry, sweetheart, I'm sure you'll ace that test.Where would I be without you, sweetheart?You make everything better.Synonyms: sweetiesteadytruelove