Learner's definition of REVISION
1 : a change or a set of changes that corrects or improves something
This edition is filled with revisions.
A revision of the theory will be necessary.
They made revisions to the book.
2 [count] : a new version of something : something (such as a piece of writing or a song) that has been corrected or changed 3 [noncount], British : study of information that was studied before