The most common and most likely answer to this crossword clue is the 6 letter word AGREES
I've seen this crossword clue in The Daily Telegraph
A
G
R
E
E
S
More clues leading to the result AGREES
- Matures, holds on, and settles
- Consents, but will be a long time coming round again
- Grease monkeys in suits
- A grand prophet goes west to get suits
- Flowing grease settles
- A grassy area cut — first requirement for Saturday matches
- View from the east on a king is in accord
- Acquiesces about entering dates
- Accepts a good wise man returning
- Matches about to go into time periods
Buddy explains!

The straight part
We know that "is in accord" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is in accord = agrees.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 AGREES mean?
AGREES verb- To harmonize in opinion, statement, or action; to be in unison or concord; to be or become united or consistent; to concur.
- To yield assent; to accede;—followed by to.
- To yield assent to; to approve.
- To make a stipulation by way of settling differences or determining a price; to exchange promises; to come to terms or to a common resolve; to promise.
- To be conformable; to resemble; to coincide; to correspond.
- (now always with with) To suit or be adapted in its effects; to do well.
- (grammar) To correspond to (another word) in a grammatical category, such as gender, number, case, or person.
- To consent to a contract or to an element of a contract.