The most common and most likely answer to this crossword clue is the 8 plus 2 plus 3 plus 5 letter word EINSTEIN ON THE BEACH
I've seen this crossword clue in The Guardian
E
I
N
S
T
E
I
N
O
N
T
H
E
B
E
A
C
H
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.