The phrase "come up short" means to fail or fall short of one's expectations or goals. There are several synonyms for this phrase that can be used to express the same idea in different ways. Some examples include: miss the mark, fall short, not make the grade, fail to meet expectations, come to a halt, hit a snag, hit a roadblock, run out of steam, fall behind schedule, and be deficient. Each of these phrases can be used to convey a sense of disappointment or frustration when something does not meet one's expectations or goals.