Anti-, 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