What is alteration by editorial criticism, as of a text so as to give a better reading; removal of errors or corruptions from a document; as, the book might be improved by judicious emendations called?

emendation — Alteration by editorial criticism, as of a text so as to give a better reading; removal of errors or corruptions from a document; as, the book might be improved by judicious emendations. (Webster's 1913.)

Sources