The most common and most likely answer to this crossword clue is the 8 letter word OMISSION
I've seen this crossword clue in The Daily Telegraph
O
M
I
S
S
I
O
N
More clues leading to the result OMISSION
- Old charitable centre reveals oversight
- It may create space over goal
- Neglect? Ring embassy
- Bond's second assignment one's overlooked
- Something left out of old assignment
- Love calling for exclusion
- Oscar’s calling for exclusion
- So scratching head with task – forgotten something?
- Lack job, love to go to the top
- Ordinary job in Gap
Buddy explains!

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 OMISSION mean?
OMISSION noun- The act of omitting.
- The act of neglecting to perform an action one has an obligation to do.
- Something deleted or left out.
- Something not done or neglected.
- (grammar) The shortening of a word or phrase, using an apostrophe ( ' ) to replace the missing letters, often used to approximate the sound of speech or a specific dialect.