omission

noun

1. 1

   The act of omitting.

2. 2

   The act of neglecting to perform an action one has an obligation to do.

3. 3

   Something deleted or left out.

   “The suspicious omissions in the new edition of the book attracted claims of censorship.”

4. 4

   Something not done or neglected.

5. 5

   (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.