The most common and most likely answer to this crossword clue is the 5 letter word FRAUD
I've seen this crossword clue in The Sunday Telegraph
F
R
A
U
D
More clues leading to the result FRAUD
- German woman departs to see swindler
- Fiddle with French car that’s dropping back
- Union member translated duck’s opening quack
- Swindling foreign woman gets close to dad
- German woman and daughter in act of deception
- Fake psychoanalyst having change of heart
- Swindle foreign woman and daughter
- German woman supported by daughter in crime
- Cheat German’s wife and daughter
- German wife had a deceptive trick
Buddy explains!

The straight part
We know that "Fake" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fake = fraud.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 FRAUD mean?
FRAUD noun- The crime of stealing or otherwise illegally obtaining money by use of deception tactics.
- Any act of deception carried out for the purpose of unfair, undeserved and/or unlawful gain.
- The assumption of a false identity to such deceptive end.
- A person who performs any such trick.
- A trap or snare.
- To defraud