ultrathin
adjective
ul·tra·thin
ˌəl-trə-ˈthin 
: extremely or extraordinarily thin
ultrathin phones
ultrathin fashion models
The molecules ride on the surface like a film of soap and assemble themselves into an ultrathin layer about one-millionth of an inch thick.—
Mike May
Mike MayExamples of ultrathin in a Sentence
a new generation of flat-panel TVs that were ultrathin
Recent Examples on the Web
In research described in Nature Nanotechnology, Jiong Lu and his colleagues at National University of Singapore and in China developed a technique that can grow a 200-millimeter sheet of a new kind of ultrathin carbon material in just 3 seconds, with no detectable impurities.
—IEEE Spectrum, 18 Aug. 2025
Manufacturers aim to create a slim and lightweight device with an ultrathin profile or complete mobility.
—Bestreviews, Mercury News, 11 Aug. 2025
The Stemless Set 6/6 Fable Glassware Set Pro (Set of 8)
$156 $140
Fable
The sleek, ultrathin rim makes these everyday glasses anything but ordinary.
—Blake Bakkila, Architectural Digest, 17 June 2025
The ultrathin blade made of Japanese carbon steel won't get discolored as easily as others, but the lack of information regarding the hardness of its blade gives me pause as to its performance in the long term.
—Molly Higgins, Wired News, 2 May 2025
See All Example Sentences for ultrathin
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.
IEEE Spectrum, 18 Aug. 2025
Manufacturers aim to create a slim and lightweight device with an ultrathin profile or complete mobility.
—Bestreviews, Mercury News, 11 Aug. 2025
The Stemless Set 6/6 Fable Glassware Set Pro (Set of 8)
$156 $140
Fable
The sleek, ultrathin rim makes these everyday glasses anything but ordinary.
—Blake Bakkila, Architectural Digest, 17 June 2025
The ultrathin blade made of Japanese carbon steel won't get discolored as easily as others, but the lack of information regarding the hardness of its blade gives me pause as to its performance in the long term.
—Molly Higgins, Wired News, 2 May 2025
See All Example Sentences for ultrathin
Cite this Entry
“Ultrathin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ultrathin. Accessed 10 Sep. 2025.
Copy CitationMedical Definition
ultrathin
adjective
ul·tra·thin
ˌəl-trə-ˈthin
: exceedingly thin
ultrathin sections for use in electron microscopy
Love words? Need even more definitions?
Merriam-Webster unabridged
Share