Synonyms of underweight

underweight

adjective

as in lightweight

having little weight

the long illness left him frail and underweight

Synonyms & Similar Words

• lightweight
• fragile
• weightless
• small
• light
• feathery
• thin
• tiny
• undersized
• puny
• featherlight
• diminutive
• petite
• smallish
• slender
• wee
• little
• slim
• flimsy
• insubstantial
• bantam
• minute
• slight

Antonyms & Near Antonyms

• overweight
• heavy
• large
• leaden
• weighty
• ponderous
• hefty
• considerable
• extensive
• substantial
• handsome
• huge
• great
• big
• massive
• super
• voluminous
• sizable
• oversize
• goodly
• jumbo
• bulky
• cumbersome
• unwieldy
• largish
• hulking
• king-size
• overscale
• whacking

Example Sentences

Recent Examples of underweight

This response was presumably adaptive to prevent our ancestors from becoming underweight but is disastrous for today’s dieters. — Literary Hub, 17 Aug. 2026

The World Remains Underweight By historical standards, gold investment remains grossly underweight. — Frank Holmes, Forbes.com, 28 July 2026

Experts told the outlets that the eagle did not suffer any broken bones or serious injuries, but had been unable to fly and is underweight. — Kimberlee Speakman, PEOPLE, 21 July 2026

Some pups were weaned early or became underweight, and more than 4,000 young sea lions were found stranded along California beaches during peak years, overwhelming rehabilitation centers. — Brandi D. Addison, USA Today, 2 July 2026