un·​der·​weight | \ ˌən-dər-ˈwāt How to pronounce underweight (audio) \

Definition of underweight

 (Entry 1 of 2)

: weight below normal, average, or requisite weight



Definition of underweight (Entry 2 of 2)

: weighing less than the normal or requisite amount

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Synonyms & Antonyms for underweight

Synonyms: Adjective

Antonyms: Adjective

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Examples of underweight in a Sentence

Adjective the long illness left him frail and underweight
Recent Examples on the Web: Noun Masato Araki, an analyst at Mitsubishi UFJ Morgan Stanley Securities Co., cut his rating on the company to underweight on Aug. 26. Toshiro Hasegawa, Bloomberg.com, "Japanese Startup Surges 300% on Demand for Cloud-Based Accounting," 4 Oct. 2020 Downgrade Beyond Meat shares fell 5.2% to $149.04 Friday after JPMorgan downgraded the stock from neutral to underweight with analysts citing that the company lost market share at grocery stores to Impossible Foods, its biggest competitor. News Services Star Tribune, Star Tribune, "Market review: Beyond Meat is downgraded as competitior grabs market share," 18 Sep. 2020 While Johnson could be at risk of being underweight, Richard determined, she was not malnourished. Annie Waldman, ProPublica, "Sent Home to Die," 2 Sep. 2020 Sometimes, multiple parasites latch on the tongue, resulting in the host fish to be underweight due to a lack of feeding. Joshua Bote, USA TODAY, "A parasite feasts on a fish's tongue until it's gone. Don't worry, humans can't get it.," 15 Aug. 2020 Piper Sandler equity analyst David Amsellem threw in the towel on Mallinckrodt, cutting his rating to underweight from neutral and slashing his price target to $1 from $3. Katherine Doherty, Bloomberg.com, "Drugmaker Mallinckrodt Weighs Bankruptcy to Ease Litigation," 3 Aug. 2020 On Tuesday, Snapchat's lead underwriter Morgan Stanley downgraded Snap from equal weight to underweight and cut its price target to $16 from $28. Krishna Thakker, Fortune, "Here’s How Many Billions Evan Spiegel Has Lost Since Snap’s IPO," 12 July 2017 Recent Examples on the Web: Adjective Josnaiber Xavier Morillo Loaiza is underweight — barely five pounds — but healthy. Isayen Herrera, New York Times, "A Mother, Her Son — and Their 1,500-Mile Search for Home," 27 Nov. 2020 At two separate inspections over the summer, the USDA found underweight bears, arthritic wolves lying on concrete, big cats with open sores caused by maggots, and an unresponsive lion cub named Nala. National Geographic, "What's going to happen to Joe Exotic's animals?," 8 Oct. 2020 Their poll generally followed the 2016 election turnout model and did not overweight or underweight groups such as Republicans. Paul Bedard, Washington Examiner, "Final Zogby: Biden 49%, Trump 43%, no ‘hidden’ voters," 2 Nov. 2020 The inspectors documented sick and injured animals, including Nala, the arthritic wolves, an underweight bear, and several unsafe enclosures, including one lemur cage that had rusted metal. Natasha Daly, National Geographic, "‘Tiger King’ zoo owner loses license, plots new animal venture," 6 Oct. 2020 Usually people with these problems are underweight and become hospitalized. Amy Dickinson, Detroit Free Press, "Eating disorder might have resurfaced, years later," 30 Sep. 2020 Usually people with these problems are underweight and become hospitalized. Amy Dickinson, oregonlive, "Ask Amy: Adolescent eating eating disorder resurfaces," 30 Sep. 2020 Usually people with these problems are underweight and become hospitalized. Washington Post, "Ask Amy: Long-ago struggle with bulimia reemerges decades later," 30 Sep. 2020 At 5-feet tall, the young woman’s weight fluctuated between 60 and 70 pounds, more than 30 pounds underweight for her size, according to the complaint. al, "A suicidal teen needed help. In Alabama, she found nothing but hurdles," 29 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'underweight.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of underweight


1596, in the meaning defined above


1675, in the meaning defined above

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Time Traveler for underweight

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 28 Feb. 2021.

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More Definitions for underweight



English Language Learners Definition of underweight

: weighing less than the normal or expected amount : too light


un·​der·​weight | \ ˌən-dər-ˈwāt How to pronounce underweight (audio) \

Kids Definition of underweight

: weighing less than what is normal, average, or necessary


un·​der·​weight | \ -ˈwāt How to pronounce underweight (audio) \

Medical Definition of underweight

: 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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