Definitions:

1. Excessive zeal or fanatism, especially when it leads to intolerance or extreme actions. NOUN
   • The zealotry of some activists can alienate potential allies.
2. Extreme passion, enthisiastm, or devotion to a cause, belief, or ideology, often accompanied by a lack of tolerance for opposing viewpoints. NOUN
   • The zealotry displayed by the group made productive dialogue nearly impossible.
3. Terms derived from the Zealots, a Jewish sect in the 1st century known for their fierce resistance against Roman rule. NOUN
   • The term 'zealotry' originates from the passionate resistance of the Zealots in ancient Judea.

Synonyms:

• enthisiasm
• exuberance
• fanaticism
• fervor
• zeal
• zealousness