The most common and most likely answer to this crossword clue is the 6 letter word BUFFER
I've seen this crossword clue in The Guardian
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More clues leading to the result BUFFER
Buddy explains!
The straight part
We know that "Polisher/protective device" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case polisher/protective device = buffer.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 BUFFER mean?
BUFFER adjective- Of the color of buff leather, a brownish yellow.
- Unusually muscular. (also buffed or buffed out)
- Physically attractive.
- Someone or something that buffs.
- A solution used to stabilize the pH (acidity) of a liquid.
- A portion of memory set aside to store data, often before it is sent to an external device or as it is received from an external device.
- (mechanical) Anything used to maintain slack or isolate different objects.
- A routine or storage medium used to compensate for a difference in rate of flow of data, or time of occurrence of events, when transferring data from one device to another.
- A device on trains and carriages designed to cushion the impact between them.
- The metal barrier to help prevent trains from running off the end of the track.
- An isolating circuit, often an amplifier, used to minimize the influence of a driven circuit on the driving circuit.
- (international relations) A buffer zone (such as a demilitarized zone) or a buffer state.
- A good-humoured, slow-witted fellow, usually an elderly man.
- A gap that isolates or separates two things.
- To use a buffer or buffers; to isolate or minimize the effects of one thing on another.
- To store data in memory temporarily.
- To maintain the acidity of a solution near a chosen value by adding an acid or a base.