The most common and most likely answer to this crossword clue is the 8 letter word CONVENOR
I've seen this crossword clue in The Guardian
C
O
N
V
E
N
O
R
Buddy explains!
The straight part
We know that "one gathers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one gathers = convenor.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 CONVENOR mean?
CONVENOR noun- One who assembles people for an official or public purpose.
- A lecturer who takes on the mantle of managing a specific course.