noun.Matter that is composed of the antiparticles of those that constitute normal matter.
noun.
A form of matter that has a key property, such as charge, opposite to that of ordinary matter.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
matter consisting of elementary particles that are the antiparticles of those making up normal substances
Word Usage
"McGregor joins the Brown franchise as Camerlegno Carlo Ventresca, a papal aide that assists Langdon and Vetra in their search for the canister in which the antimatter is contained."