The most common and most likely answer to this crossword clue is the 7 letter word DEFINES
I've seen this crossword clue in The Daily Telegraph
D
E
F
I
N
E
S
More clues leading to the result DEFINES
Buddy explains!

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 DEFINES mean?
DEFINES verb- To determine with precision; to mark out with distinctness; to ascertain or exhibit clearly.
- To settle, decide (an argument etc.)
- To express the essential nature of something.
- To state the meaning of a word, phrase, sign, or symbol.
- To describe, explain, or make definite and clear; used to request the listener or other person to elaborate or explain more clearly his or her intended meaning of a word or expression.
- To demark sharply the outlines or limits of an area or concept.
- To establish the referent of a term or notation.