underweight

1 of 2

noun

un·​der·​weight ˌən-dər-ˈwāt How to pronounce underweight (audio)
: weight below normal, average, or requisite weight

underweight

2 of 2

adjective

: weighing less than the normal or requisite amount

Examples of underweight in a Sentence

Adjective the long illness left him frail and underweight
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
When the bear cub arrived to Gold Country Wildlife Rescue in December 2024, he was dehydrated, anemic, severely underweight, suffering from ear infections in both ears and a skin infection, as previously reported by USA TODAY. Greta Cross, USA Today, 10 June 2025 Here’s what some at major shops on Wall Street had to say: Barclays keeps underweight rating and price target of $173 Analyst Tim Long’s target implies about 14% downside from Monday’s close. Lisa Kailai Han, CNBC, 10 June 2025 Stray cats tend to be underweight, unfamiliar with their surroundings, and may approach humans hesitantly. Maria Azzurra Volpe, MSNBC Newsweek, 4 June 2025 Stella’s Body Condition Score — a tool used to determine if a dog is underweight — was an abysmal 1 out of 9, the vet staff determined. Bailey Richards, People.com, 2 June 2025 See All Example Sentences for underweight

Word History

First Known Use

Noun

1596, in the meaning defined above

Adjective

1675, in the meaning defined above

Time Traveler
The first known use of underweight was in 1596

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Cite this Entry

“Underweight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underweight. Accessed 17 Jun. 2025.

Kids Definition

underweight

adjective
un·​der·​weight
ˌən-dər-ˈwāt
: weighing less than what is normal, average, or necessary

Medical Definition

underweight

adjective
un·​der·​weight -ˈwāt How to pronounce underweight (audio)
: weighing less than the normal amount for one's age, height, and build
underweight children
underweight adults typically have a body mass index of less than 18.5
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