The most common and most likely answer to this crossword clue is the 8 letter word GRADUAND
I've seen this crossword clue in The Daily Telegraph
G
R
A
D
U
A
N
D
Buddy explains!
The straight part
We know that "for one at ceremony there" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case for one at ceremony there = graduand.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 GRADUAND mean?
GRADUAND noun- A student who has completed the requirements for, but has not yet been awarded, a particular degree.