: weighing less than the normal or requisite amount
Synonyms
Examples of underweight in a Sentence
Adjective
the long illness left him frail and underweight
Recent Examples on the Web
Christian Thorsberg, Smithsonian Magazine, 15 May 2024
The 2-week-old kitten was dehydrated, underweight, had minor cuts and had an upper respiratory infection.
—Helena Wegner, Sacramento Bee, 10 May 2024
See all Example Sentences for underweight 
Adjective
The California Department of Fish and Wildlife (CDFW), along with the U.S. Fish and Wildlife Service (USFWS) and other non-governmental partners, have been working to collect and rehabilitate the birds, many of which are anemic, dehydrated and underweight.
—Christian Thorsberg, Smithsonian Magazine, 15 May 2024
The 2-week-old kitten was dehydrated, underweight, had minor cuts and had an upper respiratory infection.
—Helena Wegner, Sacramento Bee, 10 May 2024
See all Example Sentences for underweight
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“Underweight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underweight. Accessed 28 May. 2024.
Copy CitationMedical Definition
underweight
adjective
un·der·weight
-ˈwāt 
: 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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