The most common and most likely answer to this crossword clue is the 6 letter word TIPTOP
I've seen this crossword clue in The Times
T
I
P
T
O
P
More clues leading to the result TIPTOP
- Excellent advice to papa
- Fabulous shot, mine, rebounding
- Quality of vessel with stone from the east
- Excellent advice corporation rejected
- First-class spinner following helpful hint
- Excellent advice by spinner
- Turn grass up – excellent
- End to child’s toy of the highest quality
- Excellent clue to start of puzzle
- Reviewing cannabis? Mine is excellent
Buddy explains!

The straight part
We know that "Quality" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case quality = tiptop.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 TIPTOP mean?
TIPTOP noun- The very topmost point.
- The highest or utmost degree; the best of anything.
- Excellently; in a first-rate manner.