The most common and most likely answer to this crossword clue is the 4 letter word FLOP
I've seen this crossword clue in Independent
F
L
O
P
More clues leading to the result FLOP
Buddy explains!

The straight part
We know that "failure" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case failure = flop.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 FLOP mean?
FLOP noun- An incident of a certain type of fall; a plopping down.
- A complete failure, especially in the entertainment industry.
- The first three cards turned face-up by the dealer in a community card poker game.
- A ponded package of dung, as in a cow-flop.
- A flophouse.
- To fall heavily due to lack of energy.
- To cause to drop heavily.
- To fail completely; not to be successful at all (of a movie, play, book, song etc.).
- To pretend to be fouled in sports, such as basketball, hockey (the same as to dive in soccer)
- To strike about with something broad and flat, as a fish with its tail, or a bird with its wings; to rise and fall; to flap.
- To have (a hand) using the community cards dealt on the flop.
- To stay, sleep or live in a place.
- Right, squarely, flat-out.
- With a flopping sound.
- Any simple operation, such as addition, multiplication or division, performed on floating point numbers using a single operation.
- One floating-point operation per second, a unit of measure of processor speed.