The most common and most likely answer to this crossword clue is the 6 letter word AVOWAL
I've seen this crossword clue in The Guardian
A
V
O
W
A
L
More clues leading to the result AVOWAL
- Rule first cells must be set up for admission
- Admission of something that isn’t consonant, so to speak?
- Statement about rule applied to eggs
- Frank confession such as I possibly heard?
- Sounds like an ‘E’ maybe is a confession
- I heard a statement
- A girl embraced love with declaration
- Declaration of grandparent entertaining old women
- A type such as I being heard making affirmation
- Statement coming in a sort of letter read out
Buddy explains!
The straight part
We know that "declaration" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case declaration = avowal.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.