The most common and most likely answer to this crossword clue is the 7 letter word CAUSTIC
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More clues leading to the result CAUSTIC
- Sarcastic about American movement that’s not voluntary
- Scathing about American jerk
- Bitter, unending campaign meets habitual reaction
- A cut is nasty, cut initially stinging
- An example of 15 extremists in Canada and US, twitching
- Detailed reason nervous reaction is bitter in tone
- After cold, a cut is unfortunately burning
- Stinging bill rises and is cut unexpectedly
- Burning to provoke mostly instinctive reaction
- Severe military bigwig detaining an American close to unit
Buddy explains!

The straight part
We know that "Burning" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case burning = caustic.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 CAUSTIC mean?
CAUSTIC noun- Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic.
- The envelope of reflected or refracted rays of light for a given surface or object.
- The envelope of reflected or refracted rays for a given curve.
- Caustic soda.
- Capable of burning, corroding or destroying organic tissue.
- (of language, etc.) Sharp, bitter, cutting, biting, and sarcastic in a scathing way.