The most common and most likely answer to this crossword clue is the 9 letter word BEGGARING
B
E
G
G
A
R
I
N
G
Buddy explains!

The straight part
We know that "Making poor" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case making poor = beggaring.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 BEGGARING mean?
BEGGARING verb- To make a beggar of someone; impoverish.
- To exhaust the resources of; to outdo.