Anti (prefix)

1. Opposed to; against.
2. Preventing or countering.

Origin:

From ancient greek ἀντί (antí), meaning 'against'.

Examples:

1. The anti-government protest turned violent.
2. The company released an anti-smoking campaign.
3. The medicine is used as an anti-inflammatory.
4. She is against anti-vaccine beliefs.
5. The anti-lock brakes prevented the car from skidding.