The most common and most likely answer to this crossword clue is the 4 letter word PURR
P
U
R
R
More clues leading to the result PURR
- Turning up, bishop gets to express satisfaction audibly
- Sound happy for each individual to be heard
- Sound pleased to turn up with expensive motor
- Getting up, interrupted content Grinning Cat’s sound observation?
- Pulled up car making low vibrant sound
- Queen’s response to fuss possibly upset rector at university
- Sound content to reverse some of the corruption
- Rolls up duplicated content? I might
- Backing up, luxury car makes vibrating sound
- Sound of engine backing up beside expensive car
Buddy explains!

The straight part
We know that "vibrating sound" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vibrating sound = purr.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 PURR mean?
PURR noun- The vibrating sound made by a cat in its throat when contented.
- A throaty, seductive sound of pleasure made by a person.
- The low consistent rumble made by an engine at slow speed
- Of a cat, to make a vibrating sound in its throat when contented.
- To say (something) in a throaty, seductive manner.
- To make a vibrating throaty sound, as from pleasure.
- (of an engine) To make a low and consistent rumbling sound.
- Throat vibrating sound made by a cat.