The most common and most likely answer to this crossword clue is the 5 letter word ERROR
I've seen this crossword clue in The Times
E
R
R
O
R
More clues leading to the result ERROR
- Wrongdoing of troublesome brat the head expelled
- Fear losing first letter in misprint, perhaps
- Taking temperature, fear mistake
- English education requirements including nothing wrong
- Deposing leader in panic is blunder
- Bloomer gets fearsome person beheaded
- Nothing in three core subjects after English mistake
- Temperature having dropped, fear slip
- Fear losing face making this?
- Wear armour regularly, or slip
Buddy explains!

The straight part
We know that "this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this = error.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 ERROR mean?
ERROR noun- The state, quality, or condition of being wrong.
- A mistake; an accidental wrong action or a false statement not made deliberately.
- Sin; transgression.
- A failure to complete a task, usually involving a premature termination.
- The difference between a measured or calculated value and a true one.
- A play which is scored as having been made incorrectly.
- One or more mistakes in a trial that could be grounds for review of the judgement.
- Any alteration in the DNA chemical structure occurring during DNA replication, recombination or repairing.
- To function improperly due to an error, especially accompanied by error message.
- To show or contain an error or fault.
- To err.