interlineation

noun

1. A notation made between the lines, especially in a handwritten document; interlining.

   “He made the interlineation, rolled the scroll and sealed it.”

   “He turned to the table and took up a long, folded document, which I saw was done in his cramped hand and with many interlineations.”

   “Erasures, blots, interlineations always spoil the beauty of any letter.”