The most common and most likely answer to this crossword clue is the 6 letter word STATIC
I've seen this crossword clue in The Daily Telegraph
S
T
A
T
I
C
More clues leading to the result STATIC
- Still disturbance to radio reception
- Electricity in stable
- Gridlocked, perhaps, in transport leaving city
- A lot of criticism about a source of television interference
- Crackling noise on radio not mobile
- Expression of gratitude amongst a lot of criticism leaves you unmoved
- Fixed cause of poor reception
- Mush! — but not moving
- Note revolving musical boxes still
- Not my mistake, putting junk in stable
Buddy explains!

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 STATIC mean?
STATIC noun- Interference on a broadcast signal caused by atmospheric disturbances; heard as crackles on radio, or seen as random specks on television.
- (by extension) Interference or obstruction from people.
- Static electricity.
- A static caravan.
- Verbal abuse.
- A static variable.
- Unchanging; that cannot or does not change.
- Immobile; fixed in place; having no motion.
- Computed, created or allocated before the program starts running, and usually not changeable at runtime
- Defined for the class itself, as opposed to instances of it; thus shared between all instances and accessible even without an instance.