The most common and most likely answer to this crossword clue is the 2 plus 7 letter word IN ADVANCE
I've seen this crossword clue in The Guardian
I
N
A
D
V
A
N
C
E
More clues leading to the result IN ADVANCE
- Prior favoured a waltz, grabbing vicar’s top
- Notice leaders in popular church beforehand
- Going ahead with home loan
- Notice vehicle in popular church beforehand
- One name put forward beforehand
- Five were part of a gig beforehand
- New commercial vehicle restricted by freeze beforehand
- Naive and stupid, snorting cocaine earlier
- 500 against adult being bitten by naughty canine earlier
Buddy explains!

The straight part
We know that "earlier" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case earlier = in advance.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.