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

Antiprotons and positrons make up antimatter atoms, or anti-atoms. —Dipangkar Dutta, The Conversation, 15 Dec. 2025

Hospitals with radiation-emitting equipment, such as positron emission tomography scanners, sometimes release radioactive gases into the atmosphere. —Chris Baraniuk, Wired News, 15 Dec. 2025

Cosmic rays batter Earth's atmosphere constantly, interacting with molecules of air and producing showers of exotic particles such as muons, high energy neutrons and positrons. —Tereza Pultarova, Space.com, 3 Dec. 2025

The researchers used positron emission tomography (PET) scans, along with a radioactive tracer to measure the production of a chemical called acetylcholine in the participants’ brains at the start and end of the study. —Korin Miller, SELF, 23 Oct. 2025

Word History

Etymology

positive + -tron (as in electron)

First Known Use

1933, in the meaning defined above

Phrases Containing positron

• positron-emission tomography

Rhymes for positron

• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon
• chitosan
• cynodon
• denouement
• deuteron
• echelon

Kids 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