noun

• (uncountable) The act of altering for the better, or correcting what is erroneous or faulty; correction; improvement.
  "‘Aye, aye,’ quoth she, and it will be observed that no emendation whatever is necessary to be made in these two initiative remarks, ‘Aye, aye! […]"
• (countable) Alteration by editorial criticism, as of a text so as to give a better reading; removal of errors or corruptions from a document.
  "The book might be improved by judicious emendations."
• (zoology, taxonomy) An intentional change in the spelling of a scientific name, which is usually not allowed.
  "The genus name Uramyia is an unjustified emendation of Uramya even though it uses a better transliteration of the Greek word μυῖα."