The most common and most likely answer to this crossword clue is the 2 plus 4 plus 8 letter word DO ONES HOMEWORK
D
O
O
N
E
S
H
O
M
E
W
O
R
K
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.