The most common and most likely answer to this crossword clue is the 8 letter word REPEATER
I've seen this crossword clue in The Guardian
R
E
P
E
A
T
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R
More clues leading to the result REPEATER
- Electrical device consumer brought to theatre
- Perhaps watch theatre with one certain to scoff
- Rifle unloaded, safe to carry a gun
- Rifle cleared, safe to hold a gun
- Firearm of habitual criminal
- Watch parrot?
- Parrot that’s continually involved in piracy?
- Engineers safe capturing advanced weapon
- Maybe watch moth consuming material?
- Sapper, favourite after loading a Queen’s gun
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 REPEATER mean?
REPEATER noun- One who or that which repeats.
- A student repeating a course or class.
- A patient who repeatedly presents with the same symptoms.
- A consumer who repeatedly purchases the same goods or services.
- One who votes more than once at an election.
- In ufology and similar studies, a person who regularly sees unexplained sightings of paranormal phenomena.
- A gun that has a store of cartridges and does not need reloading after each shot.
- A telegraphic instrument for automatically retransmitting a message.
- An electronic device that receives a weak or low-level signal and retransmits it at a higher level or higher power.
- A watch with a striking apparatus which, upon pressure of a spring, will indicate the time, usually in hours and quarters.
- A frigate appointed to attend an admiral in a fleet, and to repeat the admiral's signals.
- A pennant used to indicate that a certain flag in a hoist of signal is duplicated.
- A repeating decimal.
- In calico printing, a design repeated at equal intervals in a pattern.