The most common and most likely answer to this crossword clue is the 5 plus 4 letter word TAKES NOTE
I've seen this crossword clue in The Daily Telegraph
T
A
K
E
S
N
O
T
E
Buddy explains!

The straight part
We know that "Observes/steals money" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case observes/steals money = takes note.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.