positron
noun
pos·i·tron
ˈpä-zə-ˌträn 
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron
called also antielectron
Examples of positron in a Sentence
Recent Examples on the Web
This is akin to what happens when an electron meets its antimatter counterpart, or positron.
—
Robert Lea, Space.com, 21 June 2026
Many caregivers first hear about PSMA when a doctor recommends a PSMA-PET (prostate-specific membrane antigen positron emission tomography) scan.
—Lauryn Higgins, Flow Space, 15 June 2026
In medical imaging, devices such as positron emission tomography scanners, or PET scanners for short, detect radiation produced when particles of antimatter – positrons – annihilate with electrons, which are normal matter.
—Christopher Karwin, The Conversation, 8 June 2026
These electrons and positrons could have enough oomph to separate the electrons from their molecules and get an avalanche going, even if the electric field stays well below the critical threshold.
—Quanta Magazine, 6 May 2026
See All Example Sentences for positron
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Robert Lea, Space.com, 21 June 2026
Many caregivers first hear about PSMA when a doctor recommends a PSMA-PET (prostate-specific membrane antigen positron emission tomography) scan.
—Lauryn Higgins, Flow Space, 15 June 2026
In medical imaging, devices such as positron emission tomography scanners, or PET scanners for short, detect radiation produced when particles of antimatter – positrons – annihilate with electrons, which are normal matter.
—Christopher Karwin, The Conversation, 8 June 2026
These electrons and positrons could have enough oomph to separate the electrons from their molecules and get an avalanche going, even if the electric field stays well below the critical threshold.
—Quanta Magazine, 6 May 2026
See All Example Sentences for positron
Cite this Entry
“Positron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/positron. Accessed 25 Jun. 2026.
Copy CitationKids Definition
positron
noun
pos·i·tron
ˈpäz-ə-ˌträn
: a positively charged particle having the same mass and size of charge as the electron
Medical Definition
positron
noun
pos·i·tron
ˈpäz-ə-ˌträn
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron
called also positive electron
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