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
Paulla King/Paulla King Violet currently weighs just 41.8 pounds—estimated to be 20 to 30 pounds underweight. Lydia Patrick, MSNBC Newsweek, 3 July 2025 His tire management mastery won the 2024 Belgian GP before Russell was ultimately disqualified for his car being underweight. Alex Kalinauckas, New York Times, 20 June 2025 But there were also broader losses in reading and math proficiency, lower preschool enrollment and a higher rate of babies born underweight. Laura Tillman, Hartford Courant, 12 June 2025 Found as a stray last August, Gilly was dangerously underweight and had clearly been through a lot. Tj MacIas, Kansas City Star, 9 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

Browse Nearby Words

Cite this Entry

“Underweight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underweight. Accessed 9 Jul. 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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