positronium

[poz-i-troh-nee-uh m]

noun Physics.

a short-lived atomic system consisting of a positron and an electron bound together.

Origin of positronium

1945; positron + -ium, coined by A. E. Ruark (born 1899), U.S. physicist

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for positronium

positronium

noun

physics a short-lived entity consisting of a positron and an electron bound together. It decays by annihilation to produce two or three photons

Word Origin for positronium

C20: from positron + -ium

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012