n.1.  The act of changing for the better; improvement: "Society may sometimes show signs of repentance and amendment" (George G. Coulton).
2.  A correction or alteration, as in a manuscript.
3. a.  The process of formally altering or adding to a document or record.
b.  A statement of such an alteration or addition.
c.   Amendment One of the provisions in the US Constitution protecting individual rights.
 4.  A material, such as organic matter or sand, mixed into soil to improve growing conditions.