matter consisting of elementary particles that are the antiparticles of those making up normal matter
antimatter详细解释
an.ti.mat.ter n.（名词）A hypothetical form of matter that is identical to physical matter except that its atoms are composed of antielectrons, antiprotons, and antineutrons.反物质：一种假想的物质形式，与自然物质相同的，只是其原子由反电子，反质子和反中子构成
