Other forms: elisions
Leaving something out is an elision. If the movie version of your favorite book leaves out the most exciting plot line, it's because the director made an elision.
Elision has its roots in the Latin word elidere, which means "to crush out." A government censor who blacks out the names of people or places in a document is making an elision, and so is an editor who removes passages from an article to make it shorter or clearer. The editor probably thinks of the elision as a clean, businesslike cut, but the writer might indeed feel crushed.