The most common and most likely answer to this crossword clue is the 8 letter word DEBACLES
I've seen this crossword clue in The Times
D
E
B
A
C
L
E
S
Buddy explains!
The straight part
We know that "Terrible failures" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case terrible failures = debacles.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 DEBACLES mean?
DEBACLES noun- An event or enterprise that ends suddenly and disastrously, often with humiliating consequences.
- A breaking up of a natural dam, usually made of ice, by a river and the ensuing rush of water.