Fervor (noun)

Great warmth and intensity of feeling.

Origin:

Late middle english: from old french fervor, from latin fervor, from fervere "be boiling, be hot", from ferrum "iron".

Examples:

1. He spoke with great fervor about the importance of education.
2. The fervor of the crowd was palpable as the game entered its final moments.
3. She approached the task with a fervor that was both admirable and a little intimidating.
4. The fervor of his religious beliefs was matched by the intensity of his political convictions.
5. The fervor of their patriotism was evident in the way they always flew the flag on national holidays.