antimatter

[an-tee-mat-er, an-tahy-] /ˈæn tiˌmæt ər, ˈæn taɪ-/

noun, Physics.

matter composed only of antiparticles, especially antiprotons, antineutrons, and positrons.

Origin

1950-55; anti- + matter

Examples from the web for antimatter

antimatter, which annihilates matter upon contact, seems to be rare in the universe.
There were only particles of matter and antimatter and light, uniformly filling all space.
Even closer to the beginning, complex physical processes set up a small excess of ordinary baryonic matter over antimatter.
Positrons are the antimatter equivalent of electrons, and are produced in a rare type of radioactive decay.
As the first pieces of matter formed, the charged conditions also created their antimatter counterparts.
One should note here that antimatter and negative matter are two entirely different things.
Parity violation is not enough to describe the matter-antimatter asymmetry.
It might, for instance, explain the preponderance of matter over antimatter in the cosmos.
The collision converts the proton into a positron, the antimatter counterpart of an electron, and a recoiling neutron.
But cyclic twin matter and antimatter universes is reality to search for further clues.

British Dictionary definitions for antimatter

/ˈæntɪˌmætə/

noun

a form of matter composed of antiparticles, such as antihydrogen, consisting of antiprotons and positrons

Word Origin and History for antimatter

also anti-matter, 1953, from anti- + matter (n.).

antimatter in Science

antimatter

(ān'tĭ-māt'ər)
A form of matter that consists of antiparticles.

antimatter in Culture