The most common and most likely answer to this crossword clue is the 2 plus 3 plus 2 plus 1 plus 4 letter word GO OUT ON A LIMB
I've seen this crossword clue in The Guardian
G
O
O
U
T
O
N
A
L
I
M
B
Buddy explains!

The straight part
We know that "Take a risk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case take a risk = go out on a limb.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.