The most common and most likely answer to this crossword clue is the 6 letter word SANEST
I've seen this crossword clue in Financial Times
S
A
N
E
S
T
More clues leading to the result SANEST
- Most balanced article written in small refuge
- Hospital in Paris is most sound
- Most balanced article plugging southern shelter
- Most balanced article on Sweden is in French
- Most sensible, wanting home in Jo’burg?
- Most reasonable hospital east of Dunkirk
- South American home is most sensible
- Extremely reasonable hospital is in Versailles
- Most Sensible Soccer aficionados need extremely strong thumbs, for starters
- Most reasonable in Salvation Army shelter
Buddy explains!

The straight part
We know that "Extremely reasonable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case extremely reasonable = sanest.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 SANEST mean?
SANEST adjective- Being in a healthy condition; not deranged; thinking rationally.
- Mentally sound; possessing a rational mind; having the mental faculties in such condition as to be able to anticipate and judge the effect of one's actions in an ordinary manner.
- Rational; reasonable; sensible.