The most common and most likely answer to this crossword clue is the 9 letter word MERCENARY
I've seen this crossword clue in The Guardian
M
E
R
C
E
N
A
R
Y
More clues leading to the result MERCENARY
- My career involved penning name for hired gun
- Hired soldier showing forbearance about near-disaster?
- Drunk consuming dinner in Spain is greedy
- Soldier’s compassion overcoming near disaster
- One happy to include lots of US money with advance?
- Money-grabbing drunk clutching broken cane
- Quivering cane held by gay person doing it for the money
Buddy explains!

The straight part
We know that "One happy to include lots of US money with advance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one happy to include lots of us money with advance = mercenary.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 MERCENARY mean?
MERCENARY noun- One motivated by gain, especially monetary.
- A person employed to fight in an armed conflict who is not a member of the state or military group for which they are fighting and whose primary motivation is private gain.
- One hired to engage in a figurative battle, as a corporate takeover, a lawsuit, or a political campaign.
- Motivated by private gain.