The most common and most likely answer to this crossword clue is the 7 letter word PAGEBOY
P
A
G
E
B
O
Y
Buddy explains!

The straight part
We know that "he accompanies bride" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case he accompanies bride = pageboy.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 PAGEBOY mean?
PAGEBOY noun- A boy who serves as a page.
- A shoulder-length hairstyle with the ends of the hair curled under.