The most common and most likely answer to this crossword clue is the 9 letter word TRIUMVIRI
T
R
I
U
M
V
I
R
I
Buddy explains!
The straight part
We know that "Chaps in office" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case chaps in office = triumviri.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 TRIUMVIRI mean?
TRIUMVIRI noun- One member of a triumvirate