The most common and most likely answer to this crossword clue is the 8 letter word ISOLATED
I've seen this crossword clue in The Guardian
I
S
O
L
A
T
E
D
More clues leading to the result ISOLATED
- Single idea lost in translation
- One very happy to skip end of dance, being lonely
- . Remote island – possibly oldest around Australia
- With no one around, I planned to eat nothing
- One dead and buried in the ground alone
- Setter eats old stew alone
- Dead, buried in ground, after one’s cut off
- One piece of turf outside recently cut off
- Remote island, very behind, gets broadband at last
- Cut off deal, so it fails
Buddy explains!

The straight part
We know that "alone" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case alone = isolated.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 ISOLATED mean?
ISOLATED verb- To set apart or cut off from others.
- To place in quarantine or isolation.
- To separate a substance in pure form from a mixture.
- To insulate, or make free of external influence.
- To separate a pure strain of bacteria etc. from a mixed culture.
- To insulate an electrical component from a source of electricity.
- Placed or standing apart or alone; in isolation.
- (of a pawn) Such that no pawn of the same color is in an adjacent file.
- (of precipitation) affecting 10 percent to 20 percent of a forecast zone.
- Which has been extracted from the organism.