From Longman Dictionary of Contemporary Englishantimatteran‧ti‧mat‧ter /ˈæntiˌmætə $ -ər/ noun [uncountable] HPa form of matter(30) (=substance which the things in the universe are made of) consisting of antiparticles
Examples from the Corpus
antimatter• Earlier we talked about antimatter - particles which have all their physical characteristics opposite to those displayed by particles of matter.• One argument is that the particles of matter and antimatter began bumping into each other and annihilating.• In the same way that matter is constituted of fundamental particles, antiparticles are the building blocks of antimatter.• Unfortunately, it seems extremely unlikely that predictable technology will be equipped to amass large quantities of antimatter.• But the device can also accelerate antiprotons, the antimatter equivalents of protons with the same mass but negative electric charge. 