semi·​per·​me·​able | \ ˌse-mē-ˈpər-mē-ə-bəl How to pronounce semipermeable (audio) , ˌse-ˌmī-, -mi- \

Definition of semipermeable

: partially but not freely or wholly permeable specifically : permeable to some usually small molecules but not to other usually larger particles a semipermeable membrane

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Other Words from semipermeable

semipermeability \ ˌse-​mē-​ˌpər-​mē-​ə-​ˈbi-​lə-​tē How to pronounce semipermeability (audio) , ˌse-​ˌmī-​ , -​mi-​ \ noun

Examples of semipermeable in a Sentence

Recent Examples on the Web Well, egg shells are semipermeable, and the older the egg, the more air can get through the shell, which explains why old eggs float. Kelsey Hurwitz, Woman's Day, "How Long Are Eggs Good For? You Can Make Them Last a While," 2 May 2020 The process of moving water across a semipermeable membrane is called osmosis. Svenja Lohner, Scientific American, "Make a Potato Shrink--with Saltwater," 9 Jan. 2020 By pumping the positive ions—like sodium or potassium—to the other side of a semipermeable membrane, researchers can create two pools of water: one with a positive charge, and one with a negative charge. Robert F. Service, Science | AAAS, "Rivers could generate thousands of nuclear power plants worth of energy, thanks to a new ‘blue’ membrane," 4 Dec. 2019 The semipermeable membranes were sheets of purple celluloid Gonzaga students had ordered from England, 135 square yards of it, at a cost of $300. John Kelly, Washington Post, "In 1969, Gonzaga students tweaked their rivals with the mother of all pranks," 5 Aug. 2019 These scientists employed a transparent capsule, made up of a semipermeable resin membrane and filled with water, to capture CO2 and then transform it into CO thanks to a light absorber coated with catalysts. Javier Garcia Martinez, Scientific American, "Artificial Leaf Turns Carbon Dioxide Into Liquid Fuel," 26 June 2017 Made from cellular material extracted from plants, the semipermeable film adheres to the outside of the avocado and slows the rate at which the avocado loses water and carbon dioxide and absorbs oxygen. Caitlin Dewey,, "This start-up can make avocados last twice as long before going bad," 19 June 2018 Those modified cells went into a body-friendly capsule equipped with a semipermeable membrane on one side to let in liquid from the gut. Megan Molteni, WIRED, "This Digital Pill Prototype Uses Bacteria to Sense Stomach Bleeding," 24 May 2018 These containers are covered by semipermeable membranes that have pores too small to allow the bacteria to escape, but just the right size to allow molecules in. David Grossman, Popular Mechanics, "Ingestible Medical Device Can Tell Your Phone What's Happening in Your Gut," 24 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'semipermeable.' 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 semipermeable

1888, in the meaning defined above

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Time Traveler for semipermeable

Time Traveler

The first known use of semipermeable was in 1888

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Statistics for semipermeable

Last Updated

6 May 2020

Cite this Entry

“Semipermeable.” Dictionary, Merriam-Webster, Accessed 5 Jul. 2020.

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More Definitions for semipermeable


semi·​per·​me·​able | \ ˌsem-i-ˈpər-mē-ə-bəl, ˌsem-ˌī- How to pronounce semipermeable (audio) \

Medical Definition of semipermeable

: partially but not freely or wholly permeable specifically : permeable to some usually small molecules but not to other usually larger particles a semipermeable membrane

Other Words from semipermeable

semipermeability \ -​ˌpər-​mē-​ə-​ˈbil-​ət-​ē How to pronounce semipermeability (audio) \ noun, plural semipermeabilities

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