The most common and most likely answer to this crossword clue is the 6 letter word NOBODY
I've seen this crossword clue in Independent
N
O
B
O
D
Y
More clues leading to the result NOBODY
- Insignificant person showing aristocrat regular letters ofgoodbye
- Diarist’s criticism of thin wine?
- What thin and tasteless wine has? Not one
- Charles Pooter's kid? One not easily deceived
- Unimportant person’s problem encountered in solving murder?
- Lightweight without substance
- Unimportant person could be problem for murder detective or winemaker
- Literary diarist translated 24 across
- On retiring, remains a person without influence
- Unnoticed person turned on by lad bearing diamonds
Buddy explains!

The straight part
We know that "Unnoticed person" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unnoticed person = nobody.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 NOBODY mean?
NOBODY noun- Someone who is not important or well-known.
- Not any person; the logical negation of somebody.