The most common and most likely answer to this crossword clue is the 5 letter word ROWDY
I've seen this crossword clue in The Daily Telegraph
R
O
W
D
Y
More clues leading to the result ROWDY
- Noisy mob, heading off before end of rally
- Argument over extremely disorderly hooligan
- Unruly mob lacking leadership, ending in disarray
- Noisy argument with daughter ending in acrimony
- Noisy argument with dandy?
- Loud argument with daddy lacking substance
- Section of the crowd yelling — what do you call it?
- Apple dessert with a different crust is tough
- Boisterous Mr. Rogers gets word in edgewise
Buddy explains!

The straight part
We know that "Noisy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case noisy = rowdy.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 ROWDY mean?
ROWDY noun- A boisterous person; a brawler.
- Loud and disorderly; riotous; boisterous.