Devotee (noun)

1. A person who is very interested in and enthusiastic about a particular activity or subject.
2. A person who is deeply devoted to a particular person, belief, or cause.

Origin:

From french dévot, from latin devōtus ("devoted"), past participle of devoveō ("i devote"), from de- ("away from") + voveō ("i vow").

Examples:

1. He was a devotee of classical music and attended every concert in the city.
2. She was a devotee of yoga and practiced every day.
3. The politician had many devoted supporters who were referred to as his devotees.
4. The new religion had many devotees who would do anything for their leader.
5. The celebrity had many devotees who would follow him everywhere.