The most common and most likely answer to this crossword clue is the 6 letter word CRITIC
I've seen this crossword clue in Independent
C
R
I
T
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C
More clues leading to the result CRITIC
- Judge a pain in the neck mostly about immigrant’s case
- Upset Catholic, Italian, I initially considered a fault-finder
- Judge’s wine imbibed by molecular biologist briefly
- One assessing most of service taken in by military boss
- Dangerous to lose a Liberal judge
- Person watching play — could be endless pain in neck about it?
- Judge starts to castigate rogue, getting one twitching
- Reviewer right to probe name largely in charge
- One quick-on-the-flaw, you might say
- Judge leaders in conspiracy rigorously in trial in court
Buddy explains!

The straight part
We know that "Reviewer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case reviewer = critic.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 CRITIC mean?
CRITIC noun- A person who appraises the works of others.
- A specialist in judging works of art.
- One who criticizes; a person who finds fault.
- An opponent.
- To criticise.
- The art of criticism.
- An essay in which another piece of work is criticised, reviewed, etc.
- A point made to criticize something.
- A critic; one who criticises.