The most common and most likely answer to this crossword clue is the 5 plus 8 letter word REITH LECTURES
I've seen this crossword clue in The Times
R
E
I
T
H
L
E
C
T
U
R
E
S
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.