The most common and most likely answer to this crossword clue is the 8 letter word ALDERMAN
I've seen this crossword clue in Financial Times
A
L
D
E
R
M
A
N
More clues leading to the result ALDERMAN
- Civic dignitary put tree on island
- Tree feller an elected council member
- Local dignitary stupidly alarmed any number
- Councillor alarmed has to change name
- Councillor and nearly all the foreign staff
- Suspect alarmed by new public official
- Official chap with less on top? Not at first
- Local politician from the South called US city about Republican
- A liberal college head entertains jolly local dignitary
- Worthy deal negotiated and managed with millions involved
Buddy explains!

The straight part
We know that "Councillor" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case councillor = alderman.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 ALDERMAN mean?
ALDERMAN noun- A member of a municipal legislative body in a city or town.
- A half-crown coin; its value, 30 pence.
- A long pipe for smoking.