- discrimination against people who are visibly overweight or obese, especially the tendency to assume that they are unhealthy and lacking in self-control, or to devalue them as unworthy of attention, unsuitable for employment, etc.: In this magazine we reject diet culture, sizeism, and the thin ideal.
- discrimination against people of a certain shape or size: Sizeism is hard to avoid on some dating apps, where users commonly request that women over 5’6” not contact them.
- discrimination on the basis of a person's size, esp against people considered to be overweight
