Rabid (adjective)

1. Having or proceeding from an extreme or fanatical support of or belief in something.
2. Affected with rabies; ferocious and uncontrollable.

Origin:

Late 16th century: from latin rabidus "mad, raging", from rabere "be mad".

Examples:

1. The fans were rabid in their support of the team.
2. The animal was rabid and had to be put down.
3. The politician's rhetoric was rabid and divisive.
4. The critics were rabid in their opposition to the new law.
5. He had a rabid hatred for the opposing team.