The most common and most likely answer to this crossword clue is the 4 letter word BETA
I've seen this crossword clue in Financial Times
B
E
T
A
More clues leading to the result BETA
- Put money on a Greek character
- Risk a second letter
- Greek character some maybe tamed
- Greek character bugged at first by another
- Punt ace, not the brightest
- Second hazard close to Scylla
- Try one’s luck with a foreign character
- Act as volunteers, getting second highest grade
- Second-class egg whisk, by the sound of it
- Soundly defeat a character from Greece
Buddy explains!

The straight part
We know that "ß" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ß = beta.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 BETA mean?
BETA noun- The second letter of the Greek alphabet (Β, β), preceded by alpha (Α, α) and followed by gamma, (Γ, γ). In modern Greek it represents the voiced labiodental fricative sound of v found in the English words have and vase.
- Used in marking scheme: α, β, γ or α+, α, α-, β etc.
- Average sensitivity of a security's price to overall securities market prices.
- The phase of development after alpha testing and before launch, in which software, while not complete, has been released to potential users for testing.
- Software in such a phase; a preliminary version.
- Information about a route which may aid someone in climbing it.
- A beta particle or beta ray.
- In omegaverse fiction, a person of a (usually secondary) gender/sex that mirrors the biology of a normal human, being free from the biological drives of alphas and omegas but generally capable of bonding and mating with either.
- To preliminarily release computer software for initial testing prior to final release.
- To beta-read a text.
- Identifying a molecular position in an organic chemical compound.
- Designates the second in an order of precedence.
- Preliminary; prerelease. Refers to an incomplete version of a product released for initial testing.
- (of a person, object or action) associated with the beta male/female archetype.
- (manosphere, pickup community) A man who is less competent or desirable than an alpha male.
- Any fish of the genus Betta, especially Betta splendens (the Siamese fighting fish).