emendation

1. The act of emending.
2. An alteration intended to improve: textual emendations made by the editor.

noun

The act or process of revising: amendment, revision, rewrite. See change/persist.

emendation, a correction made to a text in the belief that the author's original wording has been wrongly altered, e.g. by scribal error, printer's misreading, or the intervention of censorship. Unlike an amendment, which creates a fresh wording, an emendation aims to restore a lost original.

The noun has one meaning:

Meaning #1: a correction by emending; a correction resulting from critical editing