The most common and most likely answer to this crossword clue is the 4 letter word ETAS
E
T
A
S
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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 ETAS mean?
ETAS noun- The seventh letter of the Modern Greek alphabet, the eighth in Old Greek.
- A kind of electrically neutral meson having zero spin and isospin.
- A social outcast in Japan who is subjected to menial work, making up a class or caste of such people.