The most common and most likely answer to this crossword clue is the 8 letter word SCHEDULE
I've seen this crossword clue in The Times
S
C
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More clues leading to the result SCHEDULE
- Switch witless, regressive escape plan
- Agenda revolutionary Law Lord set up in Home Counties
- Agenda of revolutionary law lord brought up in Home Counties
- Avoid getting up at end of school programme
- Plan to avoid returning after school
- Avoid being upset by school’s timetable
- ‘You don’t see loafers on this,’ she’d clue cryptically
- Arrange to return foil after school
- Man had inside clues possibly for inventory
- Cryptic clues he’d put in the agenda
Buddy explains!

The straight part
We know that "plan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case plan = schedule.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 SCHEDULE mean?
SCHEDULE noun- A slip of paper; a short note.
- A written or printed table of information, often forming an annex or appendix to a statute or other regulatory instrument, or to a legal contract.
- A serial record of items, systematically arranged.
- A procedural plan, usually but not necessarily tabular in nature, indicating a sequence of operations and the planned times at which those operations are to occur.
- An allocation or ordering of a set of tasks on one or several resources.
- To create a time-schedule.
- To plan an activity at a specific date or time in the future.
- To admit (a person) to hospital as an involuntary patient under the Mental Health Act.