The most common and most likely answer to this crossword clue is the 4 plus 2 plus 3 plus 4 letter word HOLE IN THE WALL
I've seen this crossword clue in The Times
H
O
L
E
I
N
T
H
E
W
A
L
L
More clues leading to the result HOLE IN THE WALL
- Cash machine one of many appearing in Berlin in 1989?
- Source of money that once enabled East German to escape?
- Serving hatch, perhaps, where bread may be obtained
- Cash dispenser in small insignificant place
- Source of funds and wealth in Hello under review
- Source of notes and triumphant cry in time cut in room
Buddy explains!
The straight part
We know that "Cash machine" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cash machine = hole in the wall.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.