Fervent (adjective)

1. Having or showing great warmth or intensity of spirit, feeling, enthusiasm, etc.
2. Having or showing great vigor, determination, or devotion.

Origin:

From latin fervere "to boil, be hot," from ferbēre "to boil".

Examples:

1. The crowd was fervent in its support for the home team.
2. She spoke with a fervent passion for social justice.
3. He had a fervent desire to succeed in his career.
4. The singer performed with fervent energy and emotion.
5. The fervent prayers of the congregation filled the church.