Fat
Fat adjective - Having an (over)abundance of flesh.
Usage example: he hadn't remembered how fat she was
Underweight is an antonym for fat.
Underweight
Underweight adjective - Having little weight.
Both words in one sentence
- Unreliable Narrator: Hayleigh is not actually fat, but is in fact dangerously underweight.
Source: Literature / Fat -
Even the contestants portrayed as "big" or "full figured" are underweight fantastically curvy but nowhere near fat.
Source: Hollywood Thin - Many people in real life have body image issues that lead them to obsess about food and think of themselves as fat even when they're not, or even if they're trim or underweight.
Source: Hollywood Pudgy
Cite this Source
Underweight and Fat. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/fat/underweight
Fat & Underweight. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/fat/underweight>.
Underweight or Fat. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/fat/underweight.
Google Ngram Viewer shows how "fat" and "underweight" have occurred on timeline