The most common and most likely answer to this crossword clue is the 6 letter word RABBLE
I've seen this crossword clue in Independent
R
A
B
B
L
E
More clues leading to the result RABBLE
Buddy explains!

The straight part
We know that "Crowd" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case crowd = rabble.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 RABBLE mean?
RABBLE verb- To speak in a confused manner; talk incoherently; utter nonsense
- To speak confusedly or incoherently; gabble or chatter out
- A bewildered or meaningless string of words.
- A pack of animals; or any confused collection of things.
- A mob; a disorderly crowd.
- (contemptuous) The mass of common people; the lowest class of populace.
- An iron bar used in puddling.
- To stir with a rabble.