omission

1. (uncountable) The act of omitting.Examples: "Scots was not ‘banned’ outright — impossible anyway with so many Scots-speaking teachers but, like Gaelic, marginalised by omission."uncountable

2. (uncountable) The act of neglecting to perform an action one has an obligation to do.Examples: "E&O insurance (for errors and omissions) covers both errors of commission and errors of omission."uncountable

3. (countable) An instance of those acts, or the thing left out thereby; something deleted or left out.Examples: "The suspicious omissions in the new edition of the book attracted claims of censorship."countable

4. (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.countableuncountable