The most common and most likely answer to this crossword clue is the 8 letter word PREPARED
I've seen this crossword clue in The Daily Telegraph
P
R
E
P
A
R
E
D
More clues leading to the result PREPARED
- Drew up school notice about bible studies
- All set having shaved in advance?
- Public Relations copy written up, brightly-coloured, done beforehand
- Penny given fresh trim and set
- Freshly papered walls in rectory originally …
- Secretary admitting salesman’s left
- Ready peeled in advance
- Material collected by the old man, socialist geared up
- Ready before standard European debate’s beginning
- Set homework and read after revision
Buddy explains!

The straight part
We know that "Set" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case set = prepared.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 PREPARED mean?
PREPARED verb- To make ready for a specific future purpose; to set up; to assemble or equip.
- To make ready for eating or drinking; to cook.
- To make oneself ready; to get ready, make preparation.
- To produce or make by combining elements; to synthesize, compound.
- (followed by the preposition to) Disposed, willing, ready (to do something).