Definition of anti- in English:

prefix

• 1Opposed to; against.

  ‘anti-aircraft’

  1. 1.1Preventing.
     ‘antibacterial’
  2. 1.2Relieving.
     ‘antipruritic’
  3. 1.3The opposite of.
     ‘anticlimax’
     Synonyms

     dissenting, dissident, disagreeing, differing, discordant, contradicting, contrary, negative, anti-
  4. 1.4Acting as a rival.
     ‘antipope’
  5. 1.5Unlike the conventional form.
     ‘anti-hero’

• 2Physics
  The antiparticle of a specified particle.

  ‘antiproton’