Modify:
1- to change sth slightly, especially in order to make it more suitable for a particular purpose
synonym = adapt
2- to make sth less extreme
synonym =adjust
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Revise :
1- to change your opinions or plans, for example because of sth you have learned
examples:
I can see I will have to revise my opinions of his abilities now.
The government may need to revise its policy in the light of this report.
2- to change sth, such as a book or an estimate, in order to correct or improve it.
examples :
a revised edition of a textbook
I’ll prepare a revised estimate for you.
We may have to revise this figure upwards.