ultramicroscopic

adjective

ul·​tra·​mi·​cro·​scop·​ic ˌəl-trə-ˌmī-krə-ˈskä-pik How to pronounce ultramicroscopic (audio)
variants or less commonly ultramicroscopical
ˌəl-trə-ˌmī-krə-ˈskä-pi-kəl How to pronounce ultramicroscopic (audio)
1
: too small to be seen with an ordinary microscope
2
: of or relating to an ultramicroscope
ultramicroscopically
ˌəl-trə-ˌmī-krə-ˈskä-pi-k(ə-)lē How to pronounce ultramicroscopic (audio)
adverb

Word History

Etymology

International Scientific Vocabulary

First Known Use

1870, in the meaning defined at sense 1

Time Traveler
The first known use of ultramicroscopic was in 1870

Rhymes for ultramicroscopic

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Browse Nearby Words

ultramicroscope
ultramicroscopic
ultramicrotome
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Cite this Entry

“Ultramicroscopic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ultramicroscopic. Accessed 8 Jul. 2026.

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Medical Definition

ultramicroscopic

adjective
ul·​tra·​mi·​cro·​scop·​ic -ˌmī-krə-ˈskäp-ik How to pronounce ultramicroscopic (audio)
variants also ultramicroscopical
-i-kəl How to pronounce ultramicroscopic (audio)
1
: too small to be seen with an ordinary microscope compare macroscopic, microscopic sense 2, submicroscopic
2
: of or relating to an ultramicroscope
ultramicroscopically
-i-k(ə-)lē How to pronounce ultramicroscopic (audio)
adverb
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