The most common and most likely answer to this crossword clue is the 11 letter word BROTHERHOOD
I've seen this crossword clue in The Times
B
R
O
T
H
E
R
H
O
O
D
Buddy explains!
The straight part
We know that "fellowship" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fellowship = brotherhood.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 BROTHERHOOD mean?
BROTHERHOOD noun- The state of being brothers or a brother.
- An association for any purpose, such as a society of monks; a fraternity.
- The whole body of persons engaged in the same business, especially those of the same profession
- People, or (poetically) things, of the same kind.