Zealous (adjective)

Having or showing great enthusiasm and eagerness.

Origin:

The word "zealous" originated in the late 14th century, it comes from the old french word "zeleux" meaning eager, fervent.

Examples:

1. She was zealous in her pursuit of knowledge.
2. He was a zealous supporter of the cause.
3. The workers were zealous in their efforts to complete the project on time.
4. She was zealous in her devotion to her religion.
5. He was zealous in his desire to succeed.