Change a text
(Other definitions for revise that I've seen before include "Go over studies again before exam" , "Prepare for exam" , "Make changes to" , "Edit" , "Amend; cram" .)
'change a text' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for emend that I've seen before include "Edit, improve" , "Correct; edit" , "Polish" , "Correct and improve the text" , "get rid of faults" .)