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Definitions

underweight

[uhn-der-weyt, uhn-der-weyt] / ˈʌn dərˈweɪt, ˈʌn dərˌweɪt /
ADJECTIVE
thin
Synonyms
STRONGEST
malnourished starved undernourished
WEAK
angular bony gangly puny scrawny shadow skeleton skin and bones skinny stringbean undersized
Antonyms
WEAK
chubby fat overweight plump thick

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Boone was underweight, had sore ears and sore eyes when he first came into the RSPCA's care, Murphy explained.

From BBC • Apr. 9, 2026

The largest discrepancy appeared in the underweight group.

From Science Daily • Apr. 3, 2026

These tailwinds alongside cost savings prompt JPM to upgrade Lanxess’ stock to overweight from underweight.

From The Wall Street Journal • Mar. 26, 2026

It uses an individual’s weight and height to calculate a figure that fits into one of four categories: underweight, healthy weight, overweight and obesity.

From MarketWatch • Mar. 18, 2026

A dangerously underweight corporal in threadbare fatigues comes for Werner on foot.

From "All the Light We Cannot See" by Anthony Doerr