Antonyms for "be a match for" include inadequate, incapable, unable, unworthy, and inferior. When someone is unable to meet expectations, they might be described as inadequate or incapable of matching up to the challenge. Conversely, something or someone might be deemed unworthy or inferior, indicating that they are not deserving of or equivalent to the standard in question. These antonyms can convey a sense of disappointment or frustration when something or someone falls short of expectations, highlighting the importance of striving for excellence and pushing oneself to be their best.