The most common and most likely answer to this crossword clue is the 7 letter word WITNESS
I've seen this crossword clue in The Guardian
W
I
T
N
E
S
S
More clues leading to the result WITNESS
- See end of advert plugging alcoholic drink on ship
- Liberal turning to name in stupid testimony
- Twins wrong to take drugs to one appearing in court
- Observe Italian wearing wide cape
- See joker getting head
- Fake news? It’s evidence
- See top of wig — it’s on head
- See eg red and white Sierra carrying tonnes
- One observing written verses occasionally
- Name for large, foolish bystander
Buddy explains!

The straight part
We know that "one appearing in court" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one appearing in court = witness.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 WITNESS mean?
WITNESS noun- Attestation of a fact or event; testimony.
- One who sees or has personal knowledge of something.
- Someone called to give evidence in a court.
- One who is called upon to witness an event or action, such as a wedding or the signing of a document.
- Something that serves as evidence; a sign or token.
- To furnish proof of, to show.
- To take as evidence.
- To see or gain knowledge of through experience.
- (construed with to or for) To present personal religious testimony; to preach at (someone) or on behalf of.
- To see the execution of (a legal instrument), and subscribe it for the purpose of establishing its authenticity.