The most common and most likely answer to this crossword clue is the 7 letter word ROARING
I've seen this crossword clue in The Daily Telegraph
R
O
A
R
I
N
G
More clues leading to the result ROARING
Buddy explains!
The straight part
We know that "Riotous" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case riotous = roaring.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 ROARING mean?
ROARING verb- To make a loud, deep cry, especially from pain, anger, or other strong emotion.
- To laugh in a particularly loud manner.
- Of animals (especially the lion), to make a loud deep noise.
- Generally, of inanimate objects etc., to make a loud resounding noise.
- To proceed vigorously.
- To cry aloud; to proclaim loudly.
- To be boisterous; to be disorderly.
- To make a loud noise in breathing, as horses do when they have a certain disease.
- (North Midlands) to cry
- A loud, deep, prolonged sound, as of a large beast; a roar.
- An affection of the windpipe of a horse, causing a loud, peculiar noise in breathing under exertion.
- (North Midlands) to cry
- Intensive; extreme.
- Very successful; lively.