The most common and most likely answer to this crossword clue is the 8 letter word FOLLOWER
I've seen this crossword clue in The Sunday Telegraph
F
O
L
L
O
W
E
R
More clues leading to the result FOLLOWER
Buddy explains!

The straight part
We know that "Devotee" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case devotee = follower.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FOLLOWER mean?
FOLLOWER noun- One who follows, comes after another.
- Something that comes after another thing.
- One who is a part of master's physical group, such as a servant or retainer.
- One who follows mentally, adherer to the opinions, ideas or teachings of another, a movement etc.
- An imitator, who follows another's example.
- A pursuer.
- An account holder who subscribes to see content from another account on a social media platform.
- A machine part receiving motion from another.
- A man courting a maidservant.
- Young cattle.
- A metal piece placed at the top of a candle to keep the wax melting evenly.
- Any of the three players (the ruckman, ruck rover, and rover) who usually follow the ball around the ground rather than occupying a fixed position.
- A debt collector.