prefix (also ant- before a vowel or h) forming nouns and adjectives meaning: 1 opposed to; against (antivivisectionism). 2 preventing (antiscorbutic). 3 the opposite of (anticlimax). 4 rival (antipope). 5 unlike the conventional form (anti-hero; anti-novel). 6 Physics the antiparticle of a specified particle (antineutrino; antiproton).
[ from or after Gk anti- against ]