Definitions

1. adjective

having or showing a strong enthusiasm or eagerness for something, often to the point of being overly enthusiastic or fanatical.

“She was a zealous supporter of the charity, donating all her spare time and money to help with their causes.”

2. noun

a person who is very enthusiastic or eager about something.

“The team’s zealous fan was known for cheering on the team from the very first minute of the game.”