The most common and most likely answer to this crossword clue is the 6 letter word UNIQUE
I've seen this crossword clue in Financial Times
U
N
I
Q
U
E
More clues leading to the result UNIQUE
- Where we learn which of our neighbours is special
- Special noun I question to some extent
- Place of learning in Paris that’s without equal
- One and only one in French intelligence superficially usable
- . Small university in France that is like no other
- Single education centre’s quite without it
- Solitary single only
- One and only bit of fun I queried
- College, which in Paris has no peers
- What in Madrid coming after university is incomparable
Buddy explains!
The straight part
We know that "One and only" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one and only = unique.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 UNIQUE mean?
UNIQUE noun- A thing without a like; something unequalled or unparallelled.
- Being the only one of its kind; unequaled, unparalleled or unmatched.
- Of a feature, such that only one holder has it.
- Particular, characteristic.
- Of a rare quality, unusual.