The most common and most likely answer to this crossword clue is the 7 letter word FURTHER
I've seen this crossword clue in The Daily Telegraph
F
U
R
T
H
E
R
Buddy explains!
The straight part
We know that "Promote/more" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case promote/more = further.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 FURTHER mean?
FURTHER verb- To help forward; to assist.
- To encourage growth; to support progress or growth of something; to promote.
- (comparative form of far) More distant; relatively distant.
- More, additional.
- (comparative form of far) To, at or over a greater distance in space, time or other extent.
- (comparative form of far) To a greater extent or degree.
- Beyond what is already stated or is already the case.
- Also; in addition; furthermore; moreover.
- (in the phrase 'further to') Following on (from).