antimatter

Meaning

Noun

• Matter that is composed of the antiparticles of those that constitute normal matter.
• A form of matter that has a key property, such as charge, opposite to that of ordinary matter.

Origin

• From anti- + matter. to describe matter that resists gravity in a jocular article in Nature titled "Potential Matter.—A Holiday Dream", but not used in a modern sense until the 1940s.