The most common and most likely answer to this crossword clue is the 6 letter word TOPPLE
T
O
P
P
L
E
Buddy explains!
The straight part
We know that "to fall" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to fall = topple.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.
What does TOPPLE mean?
TOPPLE verb- To push, throw over, overturn or overthrow something
- To totter and fall, or to lean as if about to do so