Out-classes means surpassing, excelling, or outdoing someone or something in a particular field or area. Its antonyms include underachieving, lagging behind, falling short, and failing to meet expectations. Underperforming, below par, and inadequate are other words that describe the opposite of out-classes. Outclassed is often used to show superiority or excellence, so words like inferior, mediocre, and subpar can be used in its place. To be outclassed is to be bested, so words like defeated, beaten, overcome, and subdued can also be used as antonyms. Ultimately, finding antonyms for out-classes involves listing words that describe a lack of excellence or success.