The most common and most likely answer to this crossword clue is the 8 letter word SOLITARY
I've seen this crossword clue in The Sunday Telegraph
S
O
L
I
T
A
R
Y
More clues leading to the result SOLITARY
- Thus loving books, palace occupant disappears, shunning company?
- One confused royalist!
- Punishment that sees company barred
- Single bean plant covers wild trail
- A lone hermit
- Very turned on by Ray’s cooked sole
- Mostly reliable sailor with yen to be alone
- Rabid royalist,
- without companions
- Very bright ray bothered one
Buddy explains!

The straight part
We know that "one" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one = solitary.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 SOLITARY mean?
SOLITARY noun- One who lives alone, or in solitude; an anchoret, hermit or recluse.
- Solitary confinement.
- Living or being by oneself; alone; having no companion present
- Performed, passed, or endured alone
- Not much visited or frequented; remote from society
- Not inhabited or occupied; without signs of inhabitants or occupation; desolate; deserted
- Gloomy; dismal, because of not being inhabited.
- Single; individual; sole.
- Not associated with others of the same kind.
- The Rodrigues solitaire (Pezophaps solitaria), an extinct flightless bird.