The most common and most likely answer to this crossword clue is the 7 letter word UPSILON
I've seen this crossword clue in The Guardian
U
P
S
I
L
O
N
More clues leading to the result UPSILON
- Character well-informed on refined oil in tin
- Greek character for all to see left working alongside another?
- Erected missile site north in Europe, you say
- No lisp by upper class turns into a Greek letter
- Ancient character raised rural storage on end of plantation
- Unchecked letter?
- Letter increases capital 50% to secure a bit of interest
- Raised farm building with northern Greek character
- Greek character from university returning cured of speech impediment?
Buddy explains!
The straight part
We know that "you say" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case you say = upsilon.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 UPSILON mean?
UPSILON noun- The twentieth letter of Classical and Modern Greek; the twenty-second letter of Old and Ancient Greek.
- (particle physics) An upsilon meson, or bottomonium.