The phrase "break one's heart" refers to a feeling of extreme sadness or disappointment caused by someone or something. Antonyms for this phrase would be words that express positive emotions and feelings like happiness, satisfaction, and contentment. Some examples of antonyms for "break one's heart" are "make one's day," "lighten one's mood," "uplift one's spirit," "gratify one's soul," and "rejoice one's heart." These phrases emphasize the opposite of heartbreaks and highlight the power of positive experiences and emotions to bring joy and happiness in our lives.