The most common and most likely answer to this crossword clue is the 10 plus 4 letter word ANTHROPOID APES
I've seen this crossword clue in The Sunday Telegraph
A
N
T
H
R
O
P
O
I
D
A
P
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.