Change during meditation (4)
I believe the answer is:
edit
'change' is the definition.
(edit can mean to change or alter)
'during meditation' is the wordplay.
'during' indicates the answer is hidden within the clue.
'EDIT' is hidden in the letters of 'meditation'.
(Other definitions for edit that I've seen before include "Revise text" , "Make textual changes" , "Alter text" , "Revise for publication" , "Ready for publication" .)