semipermeable
adjective
semi·per·me·able
ˌse-mē-ˈpər-mē-ə-bəl 
ˌse-ˌmī-,
-mi-
: partially but not freely or wholly permeable
specifically
: permeable to some usually small molecules but not to other usually larger particles
a semipermeable membrane
Examples of semipermeable in a Sentence
Recent Examples on the Web
Engineering electricity from salinity gradients PRO systems work through osmosis, the process by which water molecules move from an area of low salt concentration to a high concentration across a semipermeable membrane.
—
Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025
The science behind this is based on the fact that eggshells are semipermeable, which means air can get through.
—Michelle Darrisaw, Southern Living, 30 June 2025
Reverse osmosis filters: This process forces water at high pressure through semipermeable filters, removing a larger range of contaminants such as heavy metals, bacteria, and viruses.
—Tamar Kane, Health, 6 Feb. 2023
When sprayed onto fresh produce, Iceborea becomes a natural thin film and a semipermeable barrier that can protect against microorganisms.
—Hannah Hall, Washington Post, 9 Jan. 2023
There’s a drainage line at the bottom, often under a semipermeable polymer layer that forms a firm bottom to the bunker and prevents rocks and soil from coming up during freeze-thaw cycles.
—Bradley S. Klein, WSJ, 17 June 2022
Specialized cells within the eel’s electric organ pump ions across a semipermeable membrane barrier to produce an electrical charge difference between the inside versus the outside of the membrane.
—Timothy J. Jorgensen, The Conversation, 9 May 2022
The second is whether the virus can gain access to the brain, which is protected by a semipermeable barrier that can block out pathogens and other harmful particles while still allowing nutrients and other key molecules to make it through.
—Los Angeles Times, 5 May 2021
The company C2Sense, which licensed the technology, is working on creating portable prototypes that will encapsulate the nanotubes and a tiny battery in semipermeable, food-safe material.
—Katherine Kornei, Discover Magazine, 20 Jan. 2016
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Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025
The science behind this is based on the fact that eggshells are semipermeable, which means air can get through.
—Michelle Darrisaw, Southern Living, 30 June 2025
Reverse osmosis filters: This process forces water at high pressure through semipermeable filters, removing a larger range of contaminants such as heavy metals, bacteria, and viruses.
—Tamar Kane, Health, 6 Feb. 2023
When sprayed onto fresh produce, Iceborea becomes a natural thin film and a semipermeable barrier that can protect against microorganisms.
—Hannah Hall, Washington Post, 9 Jan. 2023
There’s a drainage line at the bottom, often under a semipermeable polymer layer that forms a firm bottom to the bunker and prevents rocks and soil from coming up during freeze-thaw cycles.
—Bradley S. Klein, WSJ, 17 June 2022
Specialized cells within the eel’s electric organ pump ions across a semipermeable membrane barrier to produce an electrical charge difference between the inside versus the outside of the membrane.
—Timothy J. Jorgensen, The Conversation, 9 May 2022
The second is whether the virus can gain access to the brain, which is protected by a semipermeable barrier that can block out pathogens and other harmful particles while still allowing nutrients and other key molecules to make it through.
—Los Angeles Times, 5 May 2021
The company C2Sense, which licensed the technology, is working on creating portable prototypes that will encapsulate the nanotubes and a tiny battery in semipermeable, food-safe material.
—Katherine Kornei, Discover Magazine, 20 Jan. 2016
Cite this Entry
“Semipermeable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/semipermeable. Accessed 31 Oct. 2025.
Copy CitationKids Definition
semipermeable
adjective
semi·per·me·able
ˌsem-i-ˈpər-mē-ə-bəl
ˌsem-ˌī-
: partially but not freely or entirely permeable
especially
: permeable to some usually small molecules but not to other usually larger particles
Medical Definition
semipermeable
adjective
semi·per·me·able
ˌsem-i-ˈpər-mē-ə-bəl, ˌsem-ˌī-
: 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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