The most common and most likely answer to this crossword clue is the 7 letter word DECLARE
I've seen this crossword clue in Financial Times
D
E
C
L
A
R
E
More clues leading to the result DECLARE
- Announce editor's upset Irish county
- State capital in Delaware joining English and Irish county
- Announce two poor grades at college
- Whimsically remove 19’s county from state
- State emphatically cleared out disreputable Irish county
- Voice of awful Conservative leader
- Publish short study on Cambridge college
- Come out with first from car dealer, reconditioned
- State leader shivering, catching cold
- Assert period was first to keep 100 up
Buddy explains!

The straight part
We know that "Publish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case publish = declare.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 DECLARE mean?
DECLARE verb- To make clear, explain, interpret.
- To make a declaration.
- To show one's cards in order to score.
- To announce one’s support, choice, opinion, etc.
- For the captain of the batting side to announce the innings complete even though all batsmen have not been dismissed.
- To announce something formally or officially.
- For a constituency in an election to officially announce the result
- To affirm or state something emphatically.
- To inform government customs or taxation officials of goods one is importing or of income, expenses, or other circumstances affecting one's taxes.
- To make outstanding debts, e.g. taxes, payable.
- To explicitly establish the existence of (a variable, function, etc.) without necessarily describing its content.