The most common and most likely answer to this crossword clue is the 10 letter word CANNONBALL
I've seen this crossword clue in Independent
C
A
N
N
O
N
B
A
L
L
More clues leading to the result CANNONBALL
- Heard cleric cry loudly in quick service
- “Big shot” pair of comedians
- Tommy and Bobby make a big splash
- Shot said to make cathedral dignitary weep
- Old-fashioned projectile making churchman yell audibly
- Shot, clerical dignitary, reportedly at social function
- Shot church official pinching new orb
- Party supporting Johnson ultimately, in principle — this heavyweight must be fired
- Shot said to make cathedral cleric weep
- ‘All bacon contaminated!’ That’s gripping news making a big splash
Buddy explains!

The straight part
We know that "quick service" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case quick service = cannonball.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 CANNONBALL mean?
CANNONBALL noun- (artillery)
- The act of running and jumping in a flexed position into a swimming pool to create a large splash, mimicking the flight and shape of a cannonball.
- To jump/dive into water doing a cannonball landing.
- To careen; to move rapidly
- Yelled when jumping/diving into the water, doing a cannonball landing.