The phrase "broke one's back" typically means to work very hard or to put forth an enormous amount of effort. To offer an antonym for this phrase, we can explore some terms like "ease," "relaxation," and "leisure." These words express the opposite of intense labor or exertion. Instead of struggling, one can take it easy, kick back, or experience some repose. A few additional antonyms for "broke one's back" may include phrases like "did nothing," "slacked off," or "took the day off." Regardless of which term we choose, these antonyms all offer a counterbalance to the demanding effort suggested by "broke one's back.
