The most common and most likely answer to this crossword clue is the 6 plus 6 letter word HUMPTY DUMPTY
H
U
M
P
T
Y
D
U
M
P
T
Y
More clues leading to the result HUMPTY DUMPTY
Buddy explains!
The straight part
We know that "he fell from his perch" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case he fell from his perch = humpty dumpty.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.