The most common and most likely answer to this crossword clue is the 7 letter word NUCLEON
I've seen this crossword clue in The Guardian
N
U
C
L
E
O
N
More clues leading to the result NUCLEON
- Particle identified by Greek character, an Athenian demagogue
- Egyptian queen embraced by sister? That’s a very little matter
- Greek character, demagogue, is a fundamental constituent
- Part of London University bisecting inert gas particle
- London university splitting noble gas particle
- Central matter for physicists luncheon: rocks releasing hydrogen
- Sister embraces the Nile queen a bit?
Buddy explains!
The straight part
We know that "particle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case particle = nucleon.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 NUCLEON mean?
NUCLEON noun- One of the subatomic particles of the atomic nucleus, i.e. a proton or a neutron.