The most common and most likely answer to this crossword clue is the 8 letter word NAMELESS
I've seen this crossword clue in The Sunday Telegraph
N
A
M
E
L
E
S
S
More clues leading to the result NAMELESS
- Travelling salesmen, unknown
- Unbaptised male wrong in the head
- The French fellow having setback, ending with female unspecified
- Anonymous travelling salesmen
- Unidentified travelling salesmen
- Anonymous salesmen behaving improperly
- Unidentified rogue salesmen
- Unidentified male smashed in head
- Description of band as bad?
- Being anonymous is indescribable
Buddy explains!

The straight part
We know that "Unidentified" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unidentified = nameless.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 NAMELESS mean?
NAMELESS adjective- Not having a name; unnamed.
- Whose name is unknown; unidentified or obscure.
- Anonymous
- Unable to be described or expressed.